diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f3a116bd6..d2c7d29b7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -60,7 +60,12 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [2.7, 3.5, 3.6, 3.7, 3.8, 3.9]
+        python-version: [
+          "3.6",
+          "3.7",
+          "3.8",
+          "3.9",
+        ]
         es-version: [7.0.0, 7.10.0]
 
     steps:
diff --git a/docs/conf.py b/docs/conf.py
index 60aacdb58..c3513936f 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 #  Licensed to Elasticsearch B.V. under one or more contributor
 #  license agreements. See the NOTICE file distributed with
 #  this work for additional information regarding copyright
@@ -62,8 +61,8 @@
 master_doc = "index"
 
 # General information about the project.
-project = u"Elasticsearch DSL"
-copyright = u"%d, Elasticsearch B.V" % datetime.datetime.now().year
+project = "Elasticsearch DSL"
+copyright = "%d, Elasticsearch B.V" % datetime.datetime.now().year
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
@@ -216,8 +215,8 @@
     (
         "index",
         "Elasticsearch-dsl.tex",
-        u"Elasticsearch DSL Documentation",
-        u"Elasticsearch B.V",
+        "Elasticsearch DSL Documentation",
+        "Elasticsearch B.V",
         "manual",
     ),
 ]
@@ -251,8 +250,8 @@
     (
         "index",
         "elasticsearch-dsl",
-        u"Elasticsearch DSL Documentation",
-        [u"Elasticsearch B.V"],
+        "Elasticsearch DSL Documentation",
+        ["Elasticsearch B.V"],
         1,
     )
 ]
@@ -270,8 +269,8 @@
     (
         "index",
         "Elasticsearch",
-        u"Elasticsearch Documentation",
-        u"Elasticsearch B.V",
+        "Elasticsearch Documentation",
+        "Elasticsearch B.V",
         "Elasticsearch",
         "One line description of project.",
         "Miscellaneous",
diff --git a/elasticsearch_dsl/__init__.py b/elasticsearch_dsl/__init__.py
index a1d2ab8b2..5e157465d 100644
--- a/elasticsearch_dsl/__init__.py
+++ b/elasticsearch_dsl/__init__.py
@@ -84,7 +84,7 @@
 from .utils import AttrDict, AttrList, DslBase
 from .wrappers import Range
 
-VERSION = (7, 2, 0)
+VERSION = (8, 0, 0)
 __version__ = VERSION
 __versionstr__ = ".".join(map(str, VERSION))
 __all__ = [
diff --git a/elasticsearch_dsl/aggs.py b/elasticsearch_dsl/aggs.py
index 3b55a8ab1..8f91333aa 100644
--- a/elasticsearch_dsl/aggs.py
+++ b/elasticsearch_dsl/aggs.py
@@ -15,10 +15,7 @@
 #  specific language governing permissions and limitations
 #  under the License.
 
-try:
-    import collections.abc as collections_abc  # only works on python 3.3+
-except ImportError:
-    import collections as collections_abc
+import collections.abc
 
 from .response.aggs import AggResponse, BucketData, FieldBucketData, TopHitsData
 from .utils import DslBase
@@ -34,7 +31,7 @@ def A(name_or_agg, filter=None, **params):
         params["filter"] = filter
 
     # {"terms": {"field": "tags"}, "aggs": {...}}
-    if isinstance(name_or_agg, collections_abc.Mapping):
+    if isinstance(name_or_agg, collections.abc.Mapping):
         if params:
             raise ValueError("A() cannot accept parameters when passing in a dict.")
         # copy to avoid modifying in-place
@@ -79,7 +76,7 @@ def __contains__(self, key):
         return False
 
     def to_dict(self):
-        d = super(Agg, self).to_dict()
+        d = super().to_dict()
         if "meta" in d[self.name]:
             d["meta"] = d[self.name].pop("meta")
         return d
@@ -88,7 +85,7 @@ def result(self, search, data):
         return AggResponse(self, search, data)
 
 
-class AggBase(object):
+class AggBase:
     _param_defs = {
         "aggs": {"type": "agg", "hash": True},
     }
@@ -139,7 +136,7 @@ def result(self, search, data):
 
 class Bucket(AggBase, Agg):
     def __init__(self, **params):
-        super(Bucket, self).__init__(**params)
+        super().__init__(**params)
         # remember self for chaining
         self._base = self
 
@@ -160,10 +157,10 @@ class Filter(Bucket):
     def __init__(self, filter=None, **params):
         if filter is not None:
             params["filter"] = filter
-        super(Filter, self).__init__(**params)
+        super().__init__(**params)
 
     def to_dict(self):
-        d = super(Filter, self).to_dict()
+        d = super().to_dict()
         d[self.name].update(d[self.name].pop("filter", {}))
         return d
 
diff --git a/elasticsearch_dsl/analysis.py b/elasticsearch_dsl/analysis.py
index 115b2fab2..5277e5a1c 100644
--- a/elasticsearch_dsl/analysis.py
+++ b/elasticsearch_dsl/analysis.py
@@ -15,20 +15,18 @@
 #  specific language governing permissions and limitations
 #  under the License.
 
-import six
-
 from .connections import get_connection
 from .utils import AttrDict, DslBase, merge
 
 __all__ = ["tokenizer", "analyzer", "char_filter", "token_filter", "normalizer"]
 
 
-class AnalysisBase(object):
+class AnalysisBase:
     @classmethod
     def _type_shortcut(cls, name_or_instance, type=None, **kwargs):
         if isinstance(name_or_instance, cls):
             if type or kwargs:
-                raise ValueError("%s() cannot accept parameters." % cls.__name__)
+                raise ValueError(f"{cls.__name__}() cannot accept parameters.")
             return name_or_instance
 
         if not (type or kwargs):
@@ -39,20 +37,20 @@ def _type_shortcut(cls, name_or_instance, type=None, **kwargs):
         )
 
 
-class CustomAnalysis(object):
+class CustomAnalysis:
     name = "custom"
 
     def __init__(self, filter_name, builtin_type="custom", **kwargs):
         self._builtin_type = builtin_type
         self._name = filter_name
-        super(CustomAnalysis, self).__init__(**kwargs)
+        super().__init__(**kwargs)
 
     def to_dict(self):
         # only name to present in lists
         return self._name
 
     def get_definition(self):
-        d = super(CustomAnalysis, self).to_dict()
+        d = super().to_dict()
         d = d.pop(self.name)
         d["type"] = self._builtin_type
         return d
@@ -92,12 +90,12 @@ def get_analysis_definition(self):
         return out
 
 
-class BuiltinAnalysis(object):
+class BuiltinAnalysis:
     name = "builtin"
 
     def __init__(self, name):
         self._name = name
-        super(BuiltinAnalysis, self).__init__()
+        super().__init__()
 
     def to_dict(self):
         # only name to present in lists
@@ -148,7 +146,7 @@ def simulate(self, text, using="default", explain=False, attributes=None):
             sec_def = definition.get(section, {})
             sec_names = analyzer_def[section]
 
-            if isinstance(sec_names, six.string_types):
+            if isinstance(sec_names, str):
                 body[section] = sec_def.get(sec_names, sec_names)
             else:
                 body[section] = [
@@ -213,7 +211,7 @@ def get_definition(self):
         if "filters" in d:
             d["filters"] = [
                 # comma delimited string given by user
-                fs if isinstance(fs, six.string_types) else
+                fs if isinstance(fs, str) else
                 # list of strings or TokenFilter objects
                 ", ".join(f.to_dict() if hasattr(f, "to_dict") else f for f in fs)
                 for fs in self.filters
@@ -227,7 +225,7 @@ def get_analysis_definition(self):
         fs = {}
         d = {"filter": fs}
         for filters in self.filters:
-            if isinstance(filters, six.string_types):
+            if isinstance(filters, str):
                 continue
             fs.update(
                 {
diff --git a/elasticsearch_dsl/connections.py b/elasticsearch_dsl/connections.py
index 57ba46f1d..04b9ba43d 100644
--- a/elasticsearch_dsl/connections.py
+++ b/elasticsearch_dsl/connections.py
@@ -16,12 +16,11 @@
 #  under the License.
 
 from elasticsearch import Elasticsearch
-from six import string_types
 
 from .serializer import serializer
 
 
-class Connections(object):
+class Connections:
     """
     Class responsible for holding connections to different clusters. Used as a
     singleton in this module.
@@ -73,7 +72,7 @@ def remove_connection(self, alias):
                 errors += 1
 
         if errors == 2:
-            raise KeyError("There is no connection with alias %r." % alias)
+            raise KeyError(f"There is no connection with alias {alias!r}.")
 
     def create_connection(self, alias="default", **kwargs):
         """
@@ -95,7 +94,7 @@ def get_connection(self, alias="default"):
         """
         # do not check isinstance(Elasticsearch) so that people can wrap their
         # clients
-        if not isinstance(alias, string_types):
+        if not isinstance(alias, str):
             return alias
 
         # connection already established
@@ -109,7 +108,7 @@ def get_connection(self, alias="default"):
             return self.create_connection(alias, **self._kwargs[alias])
         except KeyError:
             # no connection and no kwargs to set one up
-            raise KeyError("There is no connection with alias %r." % alias)
+            raise KeyError(f"There is no connection with alias {alias!r}.")
 
 
 connections = Connections()
diff --git a/elasticsearch_dsl/document.py b/elasticsearch_dsl/document.py
index d68292d94..4324742fe 100644
--- a/elasticsearch_dsl/document.py
+++ b/elasticsearch_dsl/document.py
@@ -15,15 +15,10 @@
 #  specific language governing permissions and limitations
 #  under the License.
 
-try:
-    import collections.abc as collections_abc  # only works on python 3.3+
-except ImportError:
-    import collections as collections_abc
-
+import collections.abc
 from fnmatch import fnmatch
 
 from elasticsearch.exceptions import NotFoundError, RequestError
-from six import add_metaclass, iteritems
 
 from .connections import get_connection
 from .exceptions import IllegalOperation, ValidationException
@@ -34,7 +29,7 @@
 from .utils import DOC_META_FIELDS, META_FIELDS, ObjectBase, merge
 
 
-class MetaField(object):
+class MetaField:
     def __init__(self, *args, **kwargs):
         self.args, self.kwargs = args, kwargs
 
@@ -43,7 +38,7 @@ class DocumentMeta(type):
     def __new__(cls, name, bases, attrs):
         # DocumentMeta filters attrs in place
         attrs["_doc_type"] = DocumentOptions(name, bases, attrs)
-        return super(DocumentMeta, cls).__new__(cls, name, bases, attrs)
+        return super().__new__(cls, name, bases, attrs)
 
 
 class IndexMeta(DocumentMeta):
@@ -52,7 +47,7 @@ class IndexMeta(DocumentMeta):
     _document_initialized = False
 
     def __new__(cls, name, bases, attrs):
-        new_cls = super(IndexMeta, cls).__new__(cls, name, bases, attrs)
+        new_cls = super().__new__(cls, name, bases, attrs)
         if cls._document_initialized:
             index_opts = attrs.pop("Index", None)
             index = cls.construct_index(index_opts, bases)
@@ -79,7 +74,7 @@ def construct_index(cls, opts, bases):
         return i
 
 
-class DocumentOptions(object):
+class DocumentOptions:
     def __init__(self, name, bases, attrs):
         meta = attrs.pop("Meta", None)
 
@@ -87,7 +82,7 @@ def __init__(self, name, bases, attrs):
         self.mapping = getattr(meta, "mapping", Mapping())
 
         # register all declared fields into the mapping
-        for name, value in list(iteritems(attrs)):
+        for name, value in list(attrs.items()):
             if isinstance(value, Field):
                 self.mapping.field(name, value)
                 del attrs[name]
@@ -108,8 +103,7 @@ def name(self):
         return self.mapping.properties.name
 
 
-@add_metaclass(DocumentMeta)
-class InnerDoc(ObjectBase):
+class InnerDoc(ObjectBase, metaclass=DocumentMeta):
     """
     Common class for inner documents like Object or Nested
     """
@@ -118,11 +112,10 @@ class InnerDoc(ObjectBase):
     def from_es(cls, data, data_only=False):
         if data_only:
             data = {"_source": data}
-        return super(InnerDoc, cls).from_es(data)
+        return super().from_es(data)
 
 
-@add_metaclass(IndexMeta)
-class Document(ObjectBase):
+class Document(ObjectBase, metaclass=IndexMeta):
     """
     Model-like class for persisting documents in elasticsearch.
     """
@@ -170,7 +163,7 @@ def __repr__(self):
         return "{}({})".format(
             self.__class__.__name__,
             ", ".join(
-                "{}={!r}".format(key, getattr(self.meta, key))
+                f"{key}={getattr(self.meta, key)!r}"
                 for key in ("index", "id")
                 if key in self.meta
             ),
@@ -247,7 +240,7 @@ def mget(
         es = cls._get_connection(using)
         body = {
             "docs": [
-                doc if isinstance(doc, collections_abc.Mapping) else {"_id": doc}
+                doc if isinstance(doc, collections.abc.Mapping) else {"_id": doc}
                 for doc in docs
             ]
         }
@@ -282,7 +275,7 @@ def mget(
             raise RequestError(400, message, error_docs)
         if missing_docs:
             missing_ids = [doc["_id"] for doc in missing_docs]
-            message = "Documents %s not found." % ", ".join(missing_ids)
+            message = f"Documents {', '.join(missing_ids)} not found."
             raise NotFoundError(404, message, {"docs": missing_docs})
         return objs
 
@@ -321,7 +314,7 @@ def to_dict(self, include_meta=False, skip_empty=True):
             ``[]``, ``{}``) to be left on the document. Those values will be
             stripped out otherwise as they make no difference in elasticsearch.
         """
-        d = super(Document, self).to_dict(skip_empty=skip_empty)
+        d = super().to_dict(skip_empty=skip_empty)
         if not include_meta:
             return d
 
@@ -348,7 +341,7 @@ def update(
         scripted_upsert=False,
         upsert=None,
         return_doc_meta=False,
-        **fields
+        **fields,
     ):
         """
         Partial update of the document, specify fields you wish to update and
@@ -447,7 +440,7 @@ def save(
         validate=True,
         skip_empty=True,
         return_doc_meta=False,
-        **kwargs
+        **kwargs,
     ):
         """
         Save the document into elasticsearch. If the document doesn't exist it
@@ -485,7 +478,7 @@ def save(
         meta = es.index(
             index=self._get_index(index),
             body=self.to_dict(skip_empty=skip_empty),
-            **doc_meta
+            **doc_meta,
         )
         # update meta information from ES
         for k in META_FIELDS:
diff --git a/elasticsearch_dsl/faceted_search.py b/elasticsearch_dsl/faceted_search.py
index eb80b686b..395eb8225 100644
--- a/elasticsearch_dsl/faceted_search.py
+++ b/elasticsearch_dsl/faceted_search.py
@@ -17,8 +17,6 @@
 
 from datetime import datetime, timedelta
 
-from six import iteritems, itervalues
-
 from .aggs import A
 from .query import MatchAll, Nested, Range, Terms
 from .response import Response
@@ -35,7 +33,7 @@
 ]
 
 
-class Facet(object):
+class Facet:
     """
     A facet on faceted search. Wraps and aggregation and provides functionality
     to create a filter for selected values and return a list of facet values
@@ -137,7 +135,7 @@ def _range_to_dict(self, range):
         return out
 
     def __init__(self, ranges, **kwargs):
-        super(RangeFacet, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self._params["ranges"] = list(map(self._range_to_dict, ranges))
         self._params["keyed"] = False
         self._ranges = dict(ranges)
@@ -164,7 +162,7 @@ def get_value_filter(self, filter_value):
                     "gte": filter_value,
                     "lt": filter_value + self._params["interval"],
                 }
-            }
+            },
         )
 
 
@@ -208,7 +206,7 @@ class DateHistogramFacet(Facet):
 
     def __init__(self, **kwargs):
         kwargs.setdefault("min_doc_count", 0)
-        super(DateHistogramFacet, self).__init__(**kwargs)
+        super().__init__(**kwargs)
 
     def get_value(self, bucket):
         if not isinstance(bucket["key"], datetime):
@@ -237,7 +235,7 @@ def get_value_filter(self, filter_value):
                         filter_value
                     ),
                 }
-            }
+            },
         )
 
 
@@ -247,9 +245,7 @@ class NestedFacet(Facet):
     def __init__(self, path, nested_facet):
         self._path = path
         self._inner = nested_facet
-        super(NestedFacet, self).__init__(
-            path=path, aggs={"inner": nested_facet.get_aggregation()}
-        )
+        super().__init__(path=path, aggs={"inner": nested_facet.get_aggregation()})
 
     def get_values(self, data, filter_values):
         return self._inner.get_values(data.inner, filter_values)
@@ -269,7 +265,7 @@ def query_string(self):
     def facets(self):
         if not hasattr(self, "_facets"):
             super(AttrDict, self).__setattr__("_facets", AttrDict({}))
-            for name, facet in iteritems(self._faceted_search.facets):
+            for name, facet in self._faceted_search.facets.items():
                 self._facets[name] = facet.get_values(
                     getattr(getattr(self.aggregations, "_filter_" + name), name),
                     self._faceted_search.filter_values.get(name, ()),
@@ -277,7 +273,7 @@ def facets(self):
         return self._facets
 
 
-class FacetedSearch(object):
+class FacetedSearch:
     """
     Abstraction for creating faceted navigation searches that takes care of
     composing the queries, aggregations and filters as needed as well as
@@ -335,7 +331,7 @@ def __init__(self, query=None, filters={}, sort=()):
         self._filters = {}
         self._sort = sort
         self.filter_values = {}
-        for name, value in iteritems(filters):
+        for name, value in filters.items():
             self.add_filter(name, value)
 
         self._s = self.build_search()
@@ -400,10 +396,10 @@ def aggregate(self, search):
         Add aggregations representing the facets selected, including potential
         filters.
         """
-        for f, facet in iteritems(self.facets):
+        for f, facet in self.facets.items():
             agg = facet.get_aggregation()
             agg_filter = MatchAll()
-            for field, filter in iteritems(self._filters):
+            for field, filter in self._filters.items():
                 if f == field:
                     continue
                 agg_filter &= filter
@@ -420,7 +416,7 @@ def filter(self, search):
             return search
 
         post_filter = MatchAll()
-        for f in itervalues(self._filters):
+        for f in self._filters.values():
             post_filter &= f
         return search.post_filter(post_filter)
 
diff --git a/elasticsearch_dsl/field.py b/elasticsearch_dsl/field.py
index 06a10f2a2..569cf45c6 100644
--- a/elasticsearch_dsl/field.py
+++ b/elasticsearch_dsl/field.py
@@ -16,31 +16,24 @@
 #  under the License.
 
 import base64
+import collections.abc
 import copy
 import ipaddress
-
-try:
-    import collections.abc as collections_abc  # only works on python 3.3+
-except ImportError:
-    import collections as collections_abc
-
 from datetime import date, datetime
 
 from dateutil import parser, tz
-from six import integer_types, iteritems, string_types
-from six.moves import map
 
 from .exceptions import ValidationException
 from .query import Q
 from .utils import AttrDict, AttrList, DslBase
 from .wrappers import Range
 
-unicode = type(u"")
+unicode = str
 
 
 def construct_field(name_or_field, **params):
     # {"type": "text", "analyzer": "snowball"}
-    if isinstance(name_or_field, collections_abc.Mapping):
+    if isinstance(name_or_field, collections.abc.Mapping):
         if params:
             raise ValueError(
                 "construct_field() cannot accept parameters when passing in a dict."
@@ -84,7 +77,7 @@ def __init__(self, multi=False, required=False, *args, **kwargs):
         """
         self._multi = multi
         self._required = required
-        super(Field, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     def __getitem__(self, subfield):
         return self._params.get("fields", {})[subfield]
@@ -124,7 +117,7 @@ def clean(self, data):
         return data
 
     def to_dict(self):
-        d = super(Field, self).to_dict()
+        d = super().to_dict()
         name, value = d.popitem()
         value["type"] = name
         return value
@@ -138,7 +131,7 @@ def to_dict(self):
         if isinstance(self.builtin_type, Field):
             return self.builtin_type.to_dict()
 
-        d = super(CustomField, self).to_dict()
+        d = super().to_dict()
         d["type"] = self.builtin_type
         return d
 
@@ -172,13 +165,13 @@ def __init__(self, doc_class=None, dynamic=None, properties=None, **kwargs):
 
             # no InnerDoc subclass, creating one instead...
             self._doc_class = type("InnerDoc", (InnerDoc,), {})
-            for name, field in iteritems(properties or {}):
+            for name, field in (properties or {}).items():
                 self._doc_class._doc_type.mapping.field(name, field)
             if dynamic is not None:
                 self._doc_class._doc_type.mapping.meta("dynamic", dynamic)
 
         self._mapping = copy.deepcopy(self._doc_class._doc_type.mapping)
-        super(Object, self).__init__(**kwargs)
+        super().__init__(**kwargs)
 
     def __getitem__(self, name):
         return self._mapping[name]
@@ -199,7 +192,7 @@ def empty(self):
 
     def to_dict(self):
         d = self._mapping.to_dict()
-        d.update(super(Object, self).to_dict())
+        d.update(super().to_dict())
         return d
 
     def _collect_fields(self):
@@ -220,13 +213,13 @@ def _serialize(self, data):
             return None
 
         # somebody assigned raw dict to the field, we should tolerate that
-        if isinstance(data, collections_abc.Mapping):
+        if isinstance(data, collections.abc.Mapping):
             return data
 
         return data.to_dict()
 
     def clean(self, data):
-        data = super(Object, self).clean(data)
+        data = super().clean(data)
         if data is None:
             return None
         if isinstance(data, (list, AttrList)):
@@ -249,7 +242,7 @@ class Nested(Object):
 
     def __init__(self, *args, **kwargs):
         kwargs.setdefault("multi", True)
-        super(Nested, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
 
 class Date(Field):
@@ -262,17 +255,17 @@ def __init__(self, default_timezone=None, *args, **kwargs):
             May be instance of `datetime.tzinfo` or string containing TZ offset
         """
         self._default_timezone = default_timezone
-        if isinstance(self._default_timezone, string_types):
+        if isinstance(self._default_timezone, str):
             self._default_timezone = tz.gettz(self._default_timezone)
-        super(Date, self).__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs)
 
     def _deserialize(self, data):
-        if isinstance(data, string_types):
+        if isinstance(data, str):
             try:
                 data = parser.parse(data)
             except Exception as e:
                 raise ValidationException(
-                    "Could not parse date from the value (%r)" % data, e
+                    f"Could not parse date from the value ({data!r})", e
                 )
 
         if isinstance(data, datetime):
@@ -281,11 +274,11 @@ def _deserialize(self, data):
             return data
         if isinstance(data, date):
             return data
-        if isinstance(data, integer_types):
+        if isinstance(data, int):
             # Divide by a float to preserve milliseconds on the datetime.
             return datetime.utcfromtimestamp(data / 1000.0)
 
-        raise ValidationException("Could not parse date from the value (%r)" % data)
+        raise ValidationException(f"Could not parse date from the value ({data!r})")
 
 
 class Text(Field):
@@ -350,7 +343,7 @@ class DenseVector(Float):
 
     def __init__(self, dims, **kwargs):
         kwargs["multi"] = True
-        super(DenseVector, self).__init__(dims=dims, **kwargs)
+        super().__init__(dims=dims, **kwargs)
 
 
 class SparseVector(Field):
@@ -365,9 +358,7 @@ class ScaledFloat(Float):
     name = "scaled_float"
 
     def __init__(self, scaling_factor, *args, **kwargs):
-        super(ScaledFloat, self).__init__(
-            scaling_factor=scaling_factor, *args, **kwargs
-        )
+        super().__init__(scaling_factor=scaling_factor, *args, **kwargs)
 
 
 class Double(Float):
@@ -470,15 +461,15 @@ class RangeField(Field):
     def _deserialize(self, data):
         if isinstance(data, Range):
             return data
-        data = dict((k, self._core_field.deserialize(v)) for k, v in iteritems(data))
+        data = {k: self._core_field.deserialize(v) for k, v in data.items()}
         return Range(data)
 
     def _serialize(self, data):
         if data is None:
             return None
-        if not isinstance(data, collections_abc.Mapping):
+        if not isinstance(data, collections.abc.Mapping):
             data = data.to_dict()
-        return dict((k, self._core_field.serialize(v)) for k, v in iteritems(data))
+        return {k: self._core_field.serialize(v) for k, v in data.items()}
 
 
 class IntegerRange(RangeField):
diff --git a/elasticsearch_dsl/function.py b/elasticsearch_dsl/function.py
index 3e91bea86..3be9bd814 100644
--- a/elasticsearch_dsl/function.py
+++ b/elasticsearch_dsl/function.py
@@ -15,17 +15,14 @@
 #  specific language governing permissions and limitations
 #  under the License.
 
-try:
-    import collections.abc as collections_abc  # only works on python 3.3+
-except ImportError:
-    import collections as collections_abc
+import collections.abc
 
 from .utils import DslBase
 
 
 def SF(name_or_sf, **params):
     # {"script_score": {"script": "_score"}, "filter": {}}
-    if isinstance(name_or_sf, collections_abc.Mapping):
+    if isinstance(name_or_sf, collections.abc.Mapping):
         if params:
             raise ValueError("SF() cannot accept parameters when passing in a dict.")
         kwargs = {}
@@ -41,10 +38,10 @@ def SF(name_or_sf, **params):
         elif len(sf) == 1:
             name, params = sf.popitem()
         else:
-            raise ValueError("SF() got an unexpected fields in the dictionary: %r" % sf)
+            raise ValueError(f"SF() got an unexpected fields in the dictionary: {sf!r}")
 
         # boost factor special case, see elasticsearch #6343
-        if not isinstance(params, collections_abc.Mapping):
+        if not isinstance(params, collections.abc.Mapping):
             params = {"value": params}
 
         # mix known params (from _param_defs) and from inside the function
@@ -74,7 +71,7 @@ class ScoreFunction(DslBase):
     name = None
 
     def to_dict(self):
-        d = super(ScoreFunction, self).to_dict()
+        d = super().to_dict()
         # filter and query dicts should be at the same level as us
         for k in self._param_defs:
             if k in d[self.name]:
@@ -90,7 +87,7 @@ class BoostFactor(ScoreFunction):
     name = "boost_factor"
 
     def to_dict(self):
-        d = super(BoostFactor, self).to_dict()
+        d = super().to_dict()
         if "value" in d[self.name]:
             d[self.name] = d[self.name].pop("value")
         else:
diff --git a/elasticsearch_dsl/index.py b/elasticsearch_dsl/index.py
index 17dd93f45..8e8dd369b 100644
--- a/elasticsearch_dsl/index.py
+++ b/elasticsearch_dsl/index.py
@@ -24,7 +24,7 @@
 from .utils import merge
 
 
-class IndexTemplate(object):
+class IndexTemplate:
     def __init__(self, name, template, index=None, order=None, **kwargs):
         if index is None:
             self._index = Index(template, **kwargs)
@@ -55,7 +55,7 @@ def save(self, using=None):
         return es.indices.put_template(name=self._template_name, body=self.to_dict())
 
 
-class Index(object):
+class Index:
     def __init__(self, name, using="default"):
         """
         :arg name: name of the index
diff --git a/elasticsearch_dsl/mapping.py b/elasticsearch_dsl/mapping.py
index b2dd33a1c..f48608475 100644
--- a/elasticsearch_dsl/mapping.py
+++ b/elasticsearch_dsl/mapping.py
@@ -15,15 +15,9 @@
 #  specific language governing permissions and limitations
 #  under the License.
 
-try:
-    import collections.abc as collections_abc  # only works on python 3.3+
-except ImportError:
-    import collections as collections_abc
-
+import collections.abc
 from itertools import chain
 
-from six import iteritems, itervalues
-
 from .connections import get_connection
 from .field import Nested, Text, construct_field
 from .utils import DslBase
@@ -46,7 +40,7 @@ class Properties(DslBase):
     _param_defs = {"properties": {"type": "field", "hash": True}}
 
     def __init__(self):
-        super(Properties, self).__init__()
+        super().__init__()
 
     def __repr__(self):
         return "Properties()"
@@ -58,7 +52,7 @@ def __contains__(self, name):
         return name in self.properties
 
     def to_dict(self):
-        return super(Properties, self).to_dict()["properties"]
+        return super().to_dict()["properties"]
 
     def field(self, name, *args, **kwargs):
         self.properties[name] = construct_field(*args, **kwargs)
@@ -66,16 +60,14 @@ def field(self, name, *args, **kwargs):
 
     def _collect_fields(self):
         """Iterate over all Field objects within, including multi fields."""
-        for f in itervalues(self.properties.to_dict()):
+        for f in self.properties.to_dict().values():
             yield f
             # multi fields
             if hasattr(f, "fields"):
-                for inner_f in itervalues(f.fields.to_dict()):
-                    yield inner_f
+                yield from f.fields.to_dict().values()
             # nested and inner objects
             if hasattr(f, "_collect_fields"):
-                for inner_f in f._collect_fields():
-                    yield inner_f
+                yield from f._collect_fields()
 
     def update(self, other_object):
         if not hasattr(other_object, "properties"):
@@ -91,7 +83,7 @@ def update(self, other_object):
             our[name] = other[name]
 
 
-class Mapping(object):
+class Mapping:
     def __init__(self):
         self.properties = Properties()
         self._meta = {}
@@ -174,13 +166,13 @@ def update_from_es(self, index, using="default"):
         self._update_from_dict(raw["mappings"])
 
     def _update_from_dict(self, raw):
-        for name, definition in iteritems(raw.get("properties", {})):
+        for name, definition in raw.get("properties", {}).items():
             self.field(name, definition)
 
         # metadata like _all etc
-        for name, value in iteritems(raw):
+        for name, value in raw.items():
             if name != "properties":
-                if isinstance(value, collections_abc.Mapping):
+                if isinstance(value, collections.abc.Mapping):
                     self.meta(name, **value)
                 else:
                     self.meta(name, value)
diff --git a/elasticsearch_dsl/query.py b/elasticsearch_dsl/query.py
index ea58a44da..04346539f 100644
--- a/elasticsearch_dsl/query.py
+++ b/elasticsearch_dsl/query.py
@@ -15,11 +15,7 @@
 #  specific language governing permissions and limitations
 #  under the License.
 
-try:
-    import collections.abc as collections_abc  # only works on python 3.3+
-except ImportError:
-    import collections as collections_abc
-
+import collections.abc
 from itertools import chain
 
 # 'SF' looks unused but the test suite assumes it's available
@@ -31,7 +27,7 @@
 
 def Q(name_or_query="match_all", **params):
     # {"match": {"title": "python"}}
-    if isinstance(name_or_query, collections_abc.Mapping):
+    if isinstance(name_or_query, collections.abc.Mapping):
         if params:
             raise ValueError("Q() cannot accept parameters when passing in a dict.")
         if len(name_or_query) != 1:
@@ -254,7 +250,7 @@ def __init__(self, **kwargs):
             for name in ScoreFunction._classes:
                 if name in kwargs:
                     fns.append({name: kwargs.pop(name)})
-        super(FunctionScore, self).__init__(**kwargs)
+        super().__init__(**kwargs)
 
 
 # compound queries
diff --git a/elasticsearch_dsl/response/__init__.py b/elasticsearch_dsl/response/__init__.py
index 022ab158b..7af054b5b 100644
--- a/elasticsearch_dsl/response/__init__.py
+++ b/elasticsearch_dsl/response/__init__.py
@@ -25,7 +25,7 @@ class Response(AttrDict):
     def __init__(self, search, response, doc_class=None):
         super(AttrDict, self).__setattr__("_search", search)
         super(AttrDict, self).__setattr__("_doc_class", doc_class)
-        super(Response, self).__init__(response)
+        super().__init__(response)
 
     def __iter__(self):
         return iter(self.hits)
@@ -34,7 +34,7 @@ def __getitem__(self, key):
         if isinstance(key, (slice, int)):
             # for slicing etc
             return self.hits[key]
-        return super(Response, self).__getitem__(key)
+        return super().__getitem__(key)
 
     def __nonzero__(self):
         return bool(self.hits)
@@ -94,14 +94,14 @@ def aggs(self):
 class AggResponse(AttrDict):
     def __init__(self, aggs, search, data):
         super(AttrDict, self).__setattr__("_meta", {"search": search, "aggs": aggs})
-        super(AggResponse, self).__init__(data)
+        super().__init__(data)
 
     def __getitem__(self, attr_name):
         if attr_name in self._meta["aggs"]:
             # don't do self._meta['aggs'][attr_name] to avoid copying
             agg = self._meta["aggs"].aggs[attr_name]
             return agg.result(self._meta["search"], self._d_[attr_name])
-        return super(AggResponse, self).__getitem__(attr_name)
+        return super().__getitem__(attr_name)
 
     def __iter__(self):
         for name in self._meta["aggs"]:
@@ -112,7 +112,7 @@ class UpdateByQueryResponse(AttrDict):
     def __init__(self, search, response, doc_class=None):
         super(AttrDict, self).__setattr__("_search", search)
         super(AttrDict, self).__setattr__("_doc_class", doc_class)
-        super(UpdateByQueryResponse, self).__init__(response)
+        super().__init__(response)
 
     def success(self):
         return not self.timed_out and not self.failures
diff --git a/elasticsearch_dsl/response/aggs.py b/elasticsearch_dsl/response/aggs.py
index c708549f0..1f0b49bb5 100644
--- a/elasticsearch_dsl/response/aggs.py
+++ b/elasticsearch_dsl/response/aggs.py
@@ -21,14 +21,14 @@
 
 class Bucket(AggResponse):
     def __init__(self, aggs, search, data, field=None):
-        super(Bucket, self).__init__(aggs, search, data)
+        super().__init__(aggs, search, data)
 
 
 class FieldBucket(Bucket):
     def __init__(self, aggs, search, data, field=None):
         if field:
             data["key"] = field.deserialize(data["key"])
-        super(FieldBucket, self).__init__(aggs, search, data, field)
+        super().__init__(aggs, search, data, field)
 
 
 class BucketData(AggResponse):
@@ -51,7 +51,7 @@ def __len__(self):
     def __getitem__(self, key):
         if isinstance(key, (int, slice)):
             return self.buckets[key]
-        return super(BucketData, self).__getitem__(key)
+        return super().__getitem__(key)
 
     @property
     def buckets(self):
@@ -77,4 +77,4 @@ def __init__(self, agg, search, data):
         super(AttrDict, self).__setattr__(
             "meta", AttrDict({"agg": agg, "search": search})
         )
-        super(TopHitsData, self).__init__(search, data)
+        super().__init__(search, data)
diff --git a/elasticsearch_dsl/response/hit.py b/elasticsearch_dsl/response/hit.py
index ffbf40aae..7e8110f3d 100644
--- a/elasticsearch_dsl/response/hit.py
+++ b/elasticsearch_dsl/response/hit.py
@@ -26,26 +26,26 @@ def __init__(self, document):
         if "fields" in document:
             data.update(document["fields"])
 
-        super(Hit, self).__init__(data)
+        super().__init__(data)
         # assign meta as attribute and not as key in self._d_
         super(AttrDict, self).__setattr__("meta", HitMeta(document))
 
     def __getstate__(self):
         # add self.meta since it is not in self.__dict__
-        return super(Hit, self).__getstate__() + (self.meta,)
+        return super().__getstate__() + (self.meta,)
 
     def __setstate__(self, state):
         super(AttrDict, self).__setattr__("meta", state[-1])
-        super(Hit, self).__setstate__(state[:-1])
+        super().__setstate__(state[:-1])
 
     def __dir__(self):
         # be sure to expose meta in dir(self)
-        return super(Hit, self).__dir__() + ["meta"]
+        return super().__dir__() + ["meta"]
 
     def __repr__(self):
         return "<Hit({}): {}>".format(
             "/".join(
                 getattr(self.meta, key) for key in ("index", "id") if key in self.meta
             ),
-            super(Hit, self).__repr__(),
+            super().__repr__(),
         )
diff --git a/elasticsearch_dsl/search.py b/elasticsearch_dsl/search.py
index 761f6611e..c07fe7e71 100644
--- a/elasticsearch_dsl/search.py
+++ b/elasticsearch_dsl/search.py
@@ -15,16 +15,11 @@
 #  specific language governing permissions and limitations
 #  under the License.
 
+import collections.abc
 import copy
 
-try:
-    import collections.abc as collections_abc  # only works on python 3.3+
-except ImportError:
-    import collections as collections_abc
-
 from elasticsearch.exceptions import TransportError
 from elasticsearch.helpers import scan
-from six import iteritems, string_types
 
 from .aggs import A, AggBase
 from .connections import get_connection
@@ -34,7 +29,7 @@
 from .utils import AttrDict, DslBase, recursive_to_dict
 
 
-class QueryProxy(object):
+class QueryProxy:
     """
     Simple proxy around DSL objects (queries) that can be called
     (to add query/post_filter) and also allows attribute access which is proxied to
@@ -72,7 +67,7 @@ def __setattr__(self, attr_name, value):
         if not attr_name.startswith("_"):
             self._proxied = Q(self._proxied.to_dict())
             setattr(self._proxied, attr_name, value)
-        super(QueryProxy, self).__setattr__(attr_name, value)
+        super().__setattr__(attr_name, value)
 
     def __getstate__(self):
         return self._search, self._proxied, self._attr_name
@@ -81,7 +76,7 @@ def __setstate__(self, state):
         self._search, self._proxied, self._attr_name = state
 
 
-class ProxyDescriptor(object):
+class ProxyDescriptor:
     """
     Simple descriptor to enable setting of queries and filters as:
 
@@ -91,7 +86,7 @@ class ProxyDescriptor(object):
     """
 
     def __init__(self, name):
-        self._attr_name = "_%s_proxy" % name
+        self._attr_name = f"_{name}_proxy"
 
     def __get__(self, instance, owner):
         return getattr(instance, self._attr_name)
@@ -110,10 +105,10 @@ def __init__(self, search):
         self._params = {"aggs": {}}
 
     def to_dict(self):
-        return super(AggsProxy, self).to_dict().get("aggs", {})
+        return super().to_dict().get("aggs", {})
 
 
-class Request(object):
+class Request:
     def __init__(self, using="default", index=None, doc_type=None, extra=None):
         self._using = using
 
@@ -127,7 +122,7 @@ def __init__(self, using="default", index=None, doc_type=None, extra=None):
         self._doc_type_map = {}
         if isinstance(doc_type, (tuple, list)):
             self._doc_type.extend(doc_type)
-        elif isinstance(doc_type, collections_abc.Mapping):
+        elif isinstance(doc_type, collections.abc.Mapping):
             self._doc_type.extend(doc_type.keys())
             self._doc_type_map.update(doc_type)
         elif doc_type:
@@ -181,7 +176,7 @@ def index(self, *index):
         else:
             indexes = []
             for i in index:
-                if isinstance(i, string_types):
+                if isinstance(i, str):
                     indexes.append(i)
                 elif isinstance(i, list):
                     indexes += i
@@ -319,7 +314,7 @@ def __init__(self, **kwargs):
         All the parameters supplied (or omitted) at creation type can be later
         overridden by methods (`using`, `index` and `doc_type` respectively).
         """
-        super(Search, self).__init__(**kwargs)
+        super().__init__(**kwargs)
 
         self.aggs = AggsProxy(self)
         self._sort = []
@@ -407,7 +402,7 @@ def _clone(self):
         of all the underlying objects. Used internally by most state modifying
         APIs.
         """
-        s = super(Search, self)._clone()
+        s = super()._clone()
 
         s._response_class = self._response_class
         s._sort = self._sort[:]
@@ -446,7 +441,7 @@ def update_from_dict(self, d):
         aggs = d.pop("aggs", d.pop("aggregations", {}))
         if aggs:
             self.aggs._params = {
-                "aggs": {name: A(value) for (name, value) in iteritems(aggs)}
+                "aggs": {name: A(value) for (name, value) in aggs.items()}
             }
         if "sort" in d:
             self._sort = d.pop("sort")
@@ -490,7 +485,7 @@ def script_fields(self, **kwargs):
         """
         s = self._clone()
         for name in kwargs:
-            if isinstance(kwargs[name], string_types):
+            if isinstance(kwargs[name], str):
                 kwargs[name] = {"script": kwargs[name]}
         s._script_fields.update(kwargs)
         return s
@@ -566,7 +561,7 @@ def sort(self, *keys):
         s = self._clone()
         s._sort = []
         for k in keys:
-            if isinstance(k, string_types) and k.startswith("-"):
+            if isinstance(k, str) and k.startswith("-"):
                 if k[1:] == "_score":
                     raise IllegalOperation("Sorting by `-_score` is not allowed.")
                 k = {k[1:]: {"order": "desc"}}
@@ -750,7 +745,7 @@ class MultiSearch(Request):
     """
 
     def __init__(self, **kwargs):
-        super(MultiSearch, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self._searches = []
 
     def __getitem__(self, key):
@@ -760,7 +755,7 @@ def __iter__(self):
         return iter(self._searches)
 
     def _clone(self):
-        ms = super(MultiSearch, self)._clone()
+        ms = super()._clone()
         ms._searches = self._searches[:]
         return ms
 
diff --git a/elasticsearch_dsl/serializer.py b/elasticsearch_dsl/serializer.py
index 1f9832251..8336fd37f 100644
--- a/elasticsearch_dsl/serializer.py
+++ b/elasticsearch_dsl/serializer.py
@@ -26,7 +26,7 @@ def default(self, data):
             return data._l_
         if hasattr(data, "to_dict"):
             return data.to_dict()
-        return super(AttrJSONSerializer, self).default(data)
+        return super().default(data)
 
 
 serializer = AttrJSONSerializer()
diff --git a/elasticsearch_dsl/update_by_query.py b/elasticsearch_dsl/update_by_query.py
index 36e2c698b..67afdf95f 100644
--- a/elasticsearch_dsl/update_by_query.py
+++ b/elasticsearch_dsl/update_by_query.py
@@ -38,7 +38,7 @@ def __init__(self, **kwargs):
         overridden by methods (`using`, `index` and `doc_type` respectively).
 
         """
-        super(UpdateByQuery, self).__init__(**kwargs)
+        super().__init__(**kwargs)
         self._response_class = UpdateByQueryResponse
         self._script = {}
         self._query_proxy = QueryProxy(self, "query")
@@ -77,7 +77,7 @@ def _clone(self):
         of all the underlying objects. Used internally by most state modifying
         APIs.
         """
-        ubq = super(UpdateByQuery, self)._clone()
+        ubq = super()._clone()
 
         ubq._response_class = self._response_class
         ubq._script = self._script.copy()
diff --git a/elasticsearch_dsl/utils.py b/elasticsearch_dsl/utils.py
index 1f28b29fd..c362838a2 100644
--- a/elasticsearch_dsl/utils.py
+++ b/elasticsearch_dsl/utils.py
@@ -15,18 +15,10 @@
 #  specific language governing permissions and limitations
 #  under the License.
 
-from __future__ import unicode_literals
-
-try:
-    import collections.abc as collections_abc  # only works on python 3.3+
-except ImportError:
-    import collections as collections_abc
 
+import collections.abc
 from copy import copy
 
-from six import add_metaclass, iteritems
-from six.moves import map
-
 from .exceptions import UnknownDslObject, ValidationException
 
 SKIP_VALUES = ("", None)
@@ -53,14 +45,14 @@
 
 
 def _wrap(val, obj_wrapper=None):
-    if isinstance(val, collections_abc.Mapping):
+    if isinstance(val, collections.abc.Mapping):
         return AttrDict(val) if obj_wrapper is None else obj_wrapper(val)
     if isinstance(val, list):
         return AttrList(val)
     return val
 
 
-class AttrList(object):
+class AttrList:
     def __init__(self, l, obj_wrapper=None):
         # make iterables into lists
         if not isinstance(l, list):
@@ -110,7 +102,7 @@ def __setstate__(self, state):
         self._l_, self._obj_wrapper = state
 
 
-class AttrDict(object):
+class AttrDict:
     """
     Helper class to provide attribute like access (read and write) to
     dictionaries. Used to provide a convenient way to access both results and
@@ -119,7 +111,7 @@ class AttrDict(object):
 
     def __init__(self, d):
         # assign the inner dict manually to prevent __setattr__ from firing
-        super(AttrDict, self).__setattr__("_d_", d)
+        super().__setattr__("_d_", d)
 
     def __contains__(self, key):
         return key in self._d_
@@ -152,16 +144,14 @@ def __getstate__(self):
         return (self._d_,)
 
     def __setstate__(self, state):
-        super(AttrDict, self).__setattr__("_d_", state[0])
+        super().__setattr__("_d_", state[0])
 
     def __getattr__(self, attr_name):
         try:
             return self.__getitem__(attr_name)
         except KeyError:
             raise AttributeError(
-                "{!r} object has no attribute {!r}".format(
-                    self.__class__.__name__, attr_name
-                )
+                f"{self.__class__.__name__!r} object has no attribute {attr_name!r}"
             )
 
     def __delattr__(self, attr_name):
@@ -169,9 +159,7 @@ def __delattr__(self, attr_name):
             del self._d_[attr_name]
         except KeyError:
             raise AttributeError(
-                "{!r} object has no attribute {!r}".format(
-                    self.__class__.__name__, attr_name
-                )
+                f"{self.__class__.__name__!r} object has no attribute {attr_name!r}"
             )
 
     def __getitem__(self, key):
@@ -188,7 +176,7 @@ def __setattr__(self, name, value):
             self._d_[name] = value
         else:
             # there is an attribute on the class (could be property, ..) - don't add it as field
-            super(AttrDict, self).__setattr__(name, value)
+            super().__setattr__(name, value)
 
     def __iter__(self):
         return iter(self._d_)
@@ -213,7 +201,7 @@ class DslMeta(type):
     _types = {}
 
     def __init__(cls, name, bases, attrs):
-        super(DslMeta, cls).__init__(name, bases, attrs)
+        super().__init__(name, bases, attrs)
         # skip for DslBase
         if not hasattr(cls, "_type_shortcut"):
             return
@@ -232,11 +220,10 @@ def get_dsl_type(cls, name):
         try:
             return cls._types[name]
         except KeyError:
-            raise UnknownDslObject("DSL type %s does not exist." % name)
+            raise UnknownDslObject(f"DSL type {name} does not exist.")
 
 
-@add_metaclass(DslMeta)
-class DslBase(object):
+class DslBase(metaclass=DslMeta):
     """
     Base class for all DSL objects - queries, filters, aggregations etc. Wraps
     a dictionary representing the object's json.
@@ -262,12 +249,12 @@ def get_dsl_class(cls, name, default=None):
             if default is not None:
                 return cls._classes[default]
             raise UnknownDslObject(
-                "DSL class `{}` does not exist in {}.".format(name, cls._type_name)
+                f"DSL class `{name}` does not exist in {cls._type_name}."
             )
 
     def __init__(self, _expand__to_dot=EXPAND__TO_DOT, **params):
         self._params = {}
-        for pname, pvalue in iteritems(params):
+        for pname, pvalue in params.items():
             if "__" in pname and _expand__to_dot:
                 pname = pname.replace("__", ".")
             self._setattr(pname, pvalue)
@@ -275,14 +262,14 @@ def __init__(self, _expand__to_dot=EXPAND__TO_DOT, **params):
     def _repr_params(self):
         """Produce a repr of all our parameters to be used in __repr__."""
         return ", ".join(
-            "{}={!r}".format(n.replace(".", "__"), v)
-            for (n, v) in sorted(iteritems(self._params))
+            f"{n.replace('.', '__')}={v!r}"
+            for (n, v) in sorted(self._params.items())
             # make sure we don't include empty typed params
             if "type" not in self._param_defs.get(n, {}) or v
         )
 
     def __repr__(self):
-        return "{}({})".format(self.__class__.__name__, self._repr_params())
+        return f"{self.__class__.__name__}({self._repr_params()})"
 
     def __eq__(self, other):
         return isinstance(other, self.__class__) and other.to_dict() == self.to_dict()
@@ -292,7 +279,7 @@ def __ne__(self, other):
 
     def __setattr__(self, name, value):
         if name.startswith("_"):
-            return super(DslBase, self).__setattr__(name, value)
+            return super().__setattr__(name, value)
         return self._setattr(name, value)
 
     def _setattr(self, name, value):
@@ -309,7 +296,7 @@ def _setattr(self, name, value):
                     if not isinstance(value, (tuple, list)):
                         value = (value,)
                     value = list(
-                        {k: shortcut(v) for (k, v) in iteritems(obj)} for obj in value
+                        {k: shortcut(v) for (k, v) in obj.items()} for obj in value
                     )
                 elif pinfo.get("multi"):
                     if not isinstance(value, (tuple, list)):
@@ -318,7 +305,7 @@ def _setattr(self, name, value):
 
                 # dict(name -> DslBase), make sure we pickup all the objs
                 elif pinfo.get("hash"):
-                    value = {k: shortcut(v) for (k, v) in iteritems(value)}
+                    value = {k: shortcut(v) for (k, v) in value.items()}
 
                 # single value object, just convert
                 else:
@@ -328,9 +315,7 @@ def _setattr(self, name, value):
     def __getattr__(self, name):
         if name.startswith("_"):
             raise AttributeError(
-                "{!r} object has no attribute {!r}".format(
-                    self.__class__.__name__, name
-                )
+                f"{self.__class__.__name__!r} object has no attribute {name!r}"
             )
 
         value = None
@@ -347,13 +332,11 @@ def __getattr__(self, name):
                     value = self._params.setdefault(name, {})
         if value is None:
             raise AttributeError(
-                "{!r} object has no attribute {!r}".format(
-                    self.__class__.__name__, name
-                )
+                f"{self.__class__.__name__!r} object has no attribute {name!r}"
             )
 
         # wrap nested dicts in AttrDict for convenient access
-        if isinstance(value, collections_abc.Mapping):
+        if isinstance(value, collections.abc.Mapping):
             return AttrDict(value)
         return value
 
@@ -362,7 +345,7 @@ def to_dict(self):
         Serialize the DSL object to plain dict
         """
         d = {}
-        for pname, value in iteritems(self._params):
+        for pname, value in self._params.items():
             pinfo = self._param_defs.get(pname)
 
             # typed param
@@ -374,7 +357,7 @@ def to_dict(self):
                 # list of dict(name -> DslBase)
                 if pinfo.get("multi") and pinfo.get("hash"):
                     value = list(
-                        {k: v.to_dict() for k, v in iteritems(obj)} for obj in value
+                        {k: v.to_dict() for k, v in obj.items()} for obj in value
                     )
 
                 # multi-values are serialized as list of dicts
@@ -383,7 +366,7 @@ def to_dict(self):
 
                 # squash all the hash values into one dict
                 elif pinfo.get("hash"):
-                    value = {k: v.to_dict() for k, v in iteritems(value)}
+                    value = {k: v.to_dict() for k, v in value.items()}
 
                 # serialize single values
                 else:
@@ -407,13 +390,13 @@ class HitMeta(AttrDict):
     def __init__(self, document, exclude=("_source", "_fields")):
         d = {
             k[1:] if k.startswith("_") else k: v
-            for (k, v) in iteritems(document)
+            for (k, v) in document.items()
             if k not in exclude
         }
         if "type" in d:
             # make sure we are consistent everywhere in python
             d["doc_type"] = d.pop("type")
-        super(HitMeta, self).__init__(d)
+        super().__init__(d)
 
 
 class ObjectBase(AttrDict):
@@ -425,7 +408,7 @@ def __init__(self, meta=None, **kwargs):
 
         super(AttrDict, self).__setattr__("meta", HitMeta(meta))
 
-        super(ObjectBase, self).__init__(kwargs)
+        super().__init__(kwargs)
 
     @classmethod
     def __list_fields(cls):
@@ -469,7 +452,7 @@ def from_es(cls, hit):
         return doc
 
     def _from_dict(self, data):
-        for k, v in iteritems(data):
+        for k, v in data.items():
             f = self.__get_field(k)
             if f and f._coerce:
                 v = f.deserialize(v)
@@ -486,7 +469,7 @@ def __setstate__(self, state):
 
     def __getattr__(self, name):
         try:
-            return super(ObjectBase, self).__getattr__(name)
+            return super().__getattr__(name)
         except AttributeError:
             f = self.__get_field(name)
             if hasattr(f, "empty"):
@@ -499,7 +482,7 @@ def __getattr__(self, name):
 
     def to_dict(self, skip_empty=True):
         out = {}
-        for k, v in iteritems(self._d_):
+        for k, v in self._d_.items():
             # if this is a mapped field,
             f = self.__get_field(k)
             if f and f._coerce:
@@ -546,24 +529,22 @@ def full_clean(self):
 
 def merge(data, new_data, raise_on_conflict=False):
     if not (
-        isinstance(data, (AttrDict, collections_abc.Mapping))
-        and isinstance(new_data, (AttrDict, collections_abc.Mapping))
+        isinstance(data, (AttrDict, collections.abc.Mapping))
+        and isinstance(new_data, (AttrDict, collections.abc.Mapping))
     ):
         raise ValueError(
-            "You can only merge two dicts! Got {!r} and {!r} instead.".format(
-                data, new_data
-            )
+            f"You can only merge two dicts! Got {data!r} and {new_data!r} instead."
         )
 
-    for key, value in iteritems(new_data):
+    for key, value in new_data.items():
         if (
             key in data
-            and isinstance(data[key], (AttrDict, collections_abc.Mapping))
-            and isinstance(value, (AttrDict, collections_abc.Mapping))
+            and isinstance(data[key], (AttrDict, collections.abc.Mapping))
+            and isinstance(value, (AttrDict, collections.abc.Mapping))
         ):
             merge(data[key], value, raise_on_conflict)
         elif key in data and data[key] != value and raise_on_conflict:
-            raise ValueError("Incompatible data for key %r, cannot be merged." % key)
+            raise ValueError(f"Incompatible data for key {key!r}, cannot be merged.")
         else:
             data[key] = value
 
@@ -579,6 +560,6 @@ def recursive_to_dict(data):
         data = data.to_dict()
     if isinstance(data, (list, tuple)):
         return type(data)(recursive_to_dict(inner) for inner in data)
-    elif isinstance(data, collections_abc.Mapping):
+    elif isinstance(data, collections.abc.Mapping):
         return {key: recursive_to_dict(val) for key, val in data.items()}
     return data
diff --git a/elasticsearch_dsl/wrappers.py b/elasticsearch_dsl/wrappers.py
index 18d8a80ad..0dbca982f 100644
--- a/elasticsearch_dsl/wrappers.py
+++ b/elasticsearch_dsl/wrappers.py
@@ -17,8 +17,6 @@
 
 import operator
 
-from six import iteritems, string_types
-
 from .utils import AttrDict
 
 __all__ = ["Range"]
@@ -41,7 +39,7 @@ def __init__(self, *args, **kwargs):
 
         for k in data:
             if k not in self.OPS:
-                raise ValueError("Range received an unknown operator %r" % k)
+                raise ValueError(f"Range received an unknown operator {k!r}")
 
         if "gt" in data and "gte" in data:
             raise ValueError("You cannot specify both gt and gte for Range.")
@@ -49,14 +47,14 @@ def __init__(self, *args, **kwargs):
         if "lt" in data and "lte" in data:
             raise ValueError("You cannot specify both lt and lte for Range.")
 
-        super(Range, self).__init__(args[0] if args else kwargs)
+        super().__init__(args[0] if args else kwargs)
 
     def __repr__(self):
-        return "Range(%s)" % ", ".join("%s=%r" % op for op in iteritems(self._d_))
+        return "Range(%s)" % ", ".join("%s=%r" % op for op in self._d_.items())
 
     def __contains__(self, item):
-        if isinstance(item, string_types):
-            return super(Range, self).__contains__(item)
+        if isinstance(item, str):
+            return super().__contains__(item)
 
         for op in self.OPS:
             if op in self._d_ and not self.OPS[op](item, self._d_[op]):
diff --git a/examples/completion.py b/examples/completion.py
index d815a218b..8d910f1a2 100644
--- a/examples/completion.py
+++ b/examples/completion.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 #  Licensed to Elasticsearch B.V. under one or more contributor
 #  license agreements. See the NOTICE file distributed with
 #  this work for additional information regarding copyright
@@ -26,7 +25,6 @@
 To make the suggestions work in different languages we added a custom analyzer
 that does ascii folding.
 """
-from __future__ import print_function, unicode_literals
 
 from itertools import permutations
 
diff --git a/examples/composite_agg.py b/examples/composite_agg.py
index b9d22b555..a9fab676c 100644
--- a/examples/composite_agg.py
+++ b/examples/composite_agg.py
@@ -15,7 +15,6 @@
 #  specific language governing permissions and limitations
 #  under the License.
 
-from __future__ import print_function
 
 from elasticsearch_dsl import A, Search, connections
 
@@ -36,8 +35,7 @@ def run_search(**kwargs):
 
     response = run_search()
     while response.aggregations.comp.buckets:
-        for b in response.aggregations.comp.buckets:
-            yield b
+        yield from response.aggregations.comp.buckets
         if "after_key" in response.aggregations.comp:
             after = response.aggregations.comp.after_key
         else:
diff --git a/examples/parent_child.py b/examples/parent_child.py
index 3bd40964a..df832d650 100644
--- a/examples/parent_child.py
+++ b/examples/parent_child.py
@@ -113,7 +113,7 @@ def save(self, **kwargs):
         # if there is no date, use now
         if self.created is None:
             self.created = datetime.now()
-        return super(Post, self).save(**kwargs)
+        return super().save(**kwargs)
 
 
 class Question(Post):
@@ -168,7 +168,7 @@ def get_answers(self):
 
     def save(self, **kwargs):
         self.question_answer = "question"
-        return super(Question, self).save(**kwargs)
+        return super().save(**kwargs)
 
 
 class Answer(Post):
@@ -199,7 +199,7 @@ def question(self):
     def save(self, **kwargs):
         # set routing to parents id automatically
         self.meta.routing = self.question_answer.parent
-        return super(Answer, self).save(**kwargs)
+        return super().save(**kwargs)
 
 
 def setup():
diff --git a/examples/percolate.py b/examples/percolate.py
index 7ca49b635..fbe6a923a 100644
--- a/examples/percolate.py
+++ b/examples/percolate.py
@@ -53,7 +53,7 @@ def add_tags(self):
 
     def save(self, **kwargs):
         self.add_tags()
-        return super(BlogPost, self).save(**kwargs)
+        return super().save(**kwargs)
 
 
 class PercolatorDoc(Document):
diff --git a/examples/search_as_you_type.py b/examples/search_as_you_type.py
index 1c41cb73d..f82e12027 100644
--- a/examples/search_as_you_type.py
+++ b/examples/search_as_you_type.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 #  Licensed to Elasticsearch B.V. under one or more contributor
 #  license agreements. See the NOTICE file distributed with
 #  this work for additional information regarding copyright
@@ -25,7 +24,6 @@
 
 To custom analyzer with ascii folding allow search to work in different languages.
 """
-from __future__ import print_function, unicode_literals
 
 from elasticsearch_dsl import (
     Document,
diff --git a/noxfile.py b/noxfile.py
index 12ff627cb..9692783c5 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -28,7 +28,14 @@
 )
 
 
-@nox.session(python=["2.7", "3.4", "3.5", "3.6", "3.7", "3.8", "3.9"])
+@nox.session(
+    python=[
+        "3.6",
+        "3.7",
+        "3.8",
+        "3.9",
+    ]
+)
 def test(session):
     session.install(".[develop]")
 
@@ -47,9 +54,7 @@ def test(session):
 @nox.session()
 def format(session):
     session.install("black==21.12b0", "click==8.0.4", "isort")
-    session.run(
-        "black", "--target-version=py27", "--target-version=py37", *SOURCE_FILES
-    )
+    session.run("black", "--target-version=py36", *SOURCE_FILES)
     session.run("isort", *SOURCE_FILES)
     session.run("python", "utils/license-headers.py", "fix", *SOURCE_FILES)
 
@@ -59,13 +64,7 @@ def format(session):
 @nox.session
 def lint(session):
     session.install("flake8", "black==21.12b0", "click==8.0.4", "isort")
-    session.run(
-        "black",
-        "--check",
-        "--target-version=py27",
-        "--target-version=py37",
-        *SOURCE_FILES
-    )
+    session.run("black", "--check", "--target-version=py36", *SOURCE_FILES)
     session.run("isort", "--check", *SOURCE_FILES)
     session.run("flake8", "--ignore=E501,E741,W503", *SOURCE_FILES)
     session.run("python", "utils/license-headers.py", "check", *SOURCE_FILES)
diff --git a/setup.cfg b/setup.cfg
index 38d0aee11..c4b838fee 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -3,8 +3,5 @@ source-dir = docs/
 build-dir = docs/_build
 all_files = 1
 
-[wheel]
-universal = 1
-
 [isort]
 profile = black
diff --git a/setup.py b/setup.py
index 09c633053..59b52df2a 100644
--- a/setup.py
+++ b/setup.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 #  Licensed to Elasticsearch B.V. under one or more contributor
 #  license agreements. See the NOTICE file distributed with
 #  this work for additional information regarding copyright
@@ -20,7 +19,7 @@
 
 from setuptools import find_packages, setup
 
-VERSION = (7, 2, 0)
+VERSION = (8, 0, 0)
 __version__ = VERSION
 __versionstr__ = ".".join(map(str, VERSION))
 
@@ -29,15 +28,11 @@
 f.close()
 
 install_requires = [
-    "six",
     "python-dateutil",
     "elasticsearch>=7.0.0,<8.0.0",
-    # ipaddress is included in stdlib since python 3.3
-    'ipaddress; python_version<"3.3"',
 ]
 
 develop_requires = [
-    "mock",
     "pytest>=3.0.0",
     "pytest-cov",
     "pytest-mock<3.0.0",
@@ -60,18 +55,15 @@
     maintainer="Seth Michael Larson",
     maintainer_email="seth.larson@elastic.co",
     packages=find_packages(where=".", exclude=("tests*",)),
-    python_requires=">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*",
+    python_requires=">=3.6",
     classifiers=[
         "Development Status :: 4 - Beta",
         "License :: OSI Approved :: Apache Software License",
         "Intended Audience :: Developers",
         "Operating System :: OS Independent",
         "Programming Language :: Python",
-        "Programming Language :: Python :: 2",
-        "Programming Language :: Python :: 2.7",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.4",
-        "Programming Language :: Python :: 3.5",
+        "Programming Language :: Python :: 3 :: Only",
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
diff --git a/tests/conftest.py b/tests/conftest.py
index b7326c3fb..09c092890 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 #  Licensed to Elasticsearch B.V. under one or more contributor
 #  license agreements. See the NOTICE file distributed with
 #  this work for additional information regarding copyright
@@ -20,10 +19,10 @@
 import os
 import re
 from datetime import datetime
+from unittest.mock import Mock
 
 from elasticsearch.helpers import bulk
 from elasticsearch.helpers.test import SkipTest, get_test_client
-from mock import Mock
 from pytest import fixture, skip
 
 from elasticsearch_dsl.connections import add_connection, connections
diff --git a/tests/test_analysis.py b/tests/test_analysis.py
index 90445502b..eec08baec 100644
--- a/tests/test_analysis.py
+++ b/tests/test_analysis.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 #  Licensed to Elasticsearch B.V. under one or more contributor
 #  license agreements. See the NOTICE file distributed with
 #  this work for additional information regarding copyright
diff --git a/tests/test_document.py b/tests/test_document.py
index 5e34f0dbb..3660d9bec 100644
--- a/tests/test_document.py
+++ b/tests/test_document.py
@@ -170,7 +170,7 @@ class B(document.Document):
 
 
 def test_ip_address_serializes_properly():
-    host = Host(ip=ipaddress.IPv4Address(u"10.0.0.1"))
+    host = Host(ip=ipaddress.IPv4Address("10.0.0.1"))
 
     assert {"ip": "10.0.0.1"} == host.to_dict()
 
diff --git a/tests/test_field.py b/tests/test_field.py
index 8bc8d6f03..91011af95 100644
--- a/tests/test_field.py
+++ b/tests/test_field.py
@@ -141,8 +141,8 @@ def test_scaled_float():
 
 def test_ipaddress():
     f = field.Ip()
-    assert f.deserialize("127.0.0.1") == ipaddress.ip_address(u"127.0.0.1")
-    assert f.deserialize(u"::1") == ipaddress.ip_address(u"::1")
+    assert f.deserialize("127.0.0.1") == ipaddress.ip_address("127.0.0.1")
+    assert f.deserialize("::1") == ipaddress.ip_address("::1")
     assert f.serialize(f.deserialize("::1")) == "::1"
     assert f.deserialize(None) is None
     with pytest.raises(ValueError):
diff --git a/tests/test_index.py b/tests/test_index.py
index 3bdddb57b..420160e50 100644
--- a/tests/test_index.py
+++ b/tests/test_index.py
@@ -74,7 +74,7 @@ def test_cloned_index_has_analysis_attribute():
     client = object()
     i = Index("my-index", using=client)
 
-    random_analyzer_name = "".join((choice(string.ascii_letters) for _ in range(100)))
+    random_analyzer_name = "".join(choice(string.ascii_letters) for _ in range(100))
     random_analyzer = analyzer(
         random_analyzer_name, tokenizer="standard", filter="standard"
     )
@@ -118,7 +118,7 @@ def test_registered_doc_type_included_in_search():
 
 
 def test_aliases_add_to_object():
-    random_alias = "".join((choice(string.ascii_letters) for _ in range(100)))
+    random_alias = "".join(choice(string.ascii_letters) for _ in range(100))
     alias_dict = {random_alias: {}}
 
     index = Index("i", using="alias")
@@ -128,7 +128,7 @@ def test_aliases_add_to_object():
 
 
 def test_aliases_returned_from_to_dict():
-    random_alias = "".join((choice(string.ascii_letters) for _ in range(100)))
+    random_alias = "".join(choice(string.ascii_letters) for _ in range(100))
     alias_dict = {random_alias: {}}
 
     index = Index("i", using="alias")
@@ -138,7 +138,7 @@ def test_aliases_returned_from_to_dict():
 
 
 def test_analyzers_added_to_object():
-    random_analyzer_name = "".join((choice(string.ascii_letters) for _ in range(100)))
+    random_analyzer_name = "".join(choice(string.ascii_letters) for _ in range(100))
     random_analyzer = analyzer(
         random_analyzer_name, tokenizer="standard", filter="standard"
     )
@@ -154,7 +154,7 @@ def test_analyzers_added_to_object():
 
 
 def test_analyzers_returned_from_to_dict():
-    random_analyzer_name = "".join((choice(string.ascii_letters) for _ in range(100)))
+    random_analyzer_name = "".join(choice(string.ascii_letters) for _ in range(100))
     random_analyzer = analyzer(
         random_analyzer_name, tokenizer="standard", filter="standard"
     )
diff --git a/tests/test_integration/test_data.py b/tests/test_integration/test_data.py
index 958f528b3..c78b6301a 100644
--- a/tests/test_integration/test_data.py
+++ b/tests/test_integration/test_data.py
@@ -15,8 +15,6 @@
 #  specific language governing permissions and limitations
 #  under the License.
 
-from __future__ import unicode_literals
-
 
 def create_flat_git_index(client, index):
     # we will use user on several places
diff --git a/tests/test_integration/test_document.py b/tests/test_integration/test_document.py
index 908de1d21..52600afdc 100644
--- a/tests/test_integration/test_document.py
+++ b/tests/test_integration/test_document.py
@@ -68,7 +68,7 @@ class Repository(Document):
 
     @classmethod
     def search(cls):
-        return super(Repository, cls).search().filter("term", commit_repo="repo")
+        return super().search().filter("term", commit_repo="repo")
 
     class Index:
         name = "git"
@@ -139,7 +139,7 @@ def test_serialization(write_client):
     assert sd.b == [True, False, True, False, None]
     assert sd.d == [0.1, -0.1, None]
     assert sd.bin == [b"Hello World", None]
-    assert sd.ip == [ip_address(u"::1"), ip_address(u"127.0.0.1"), None]
+    assert sd.ip == [ip_address("::1"), ip_address("127.0.0.1"), None]
 
     assert sd.to_dict() == {
         "b": [True, False, True, False, None],
diff --git a/tests/test_integration/test_examples/test_completion.py b/tests/test_integration/test_examples/test_completion.py
index 42aef0db2..92f6d80a0 100644
--- a/tests/test_integration/test_examples/test_completion.py
+++ b/tests/test_integration/test_examples/test_completion.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 #  Licensed to Elasticsearch B.V. under one or more contributor
 #  license agreements. See the NOTICE file distributed with
 #  this work for additional information regarding copyright
@@ -16,7 +15,6 @@
 #  specific language governing permissions and limitations
 #  under the License.
 
-from __future__ import unicode_literals
 
 from .completion import Person
 
diff --git a/tests/test_integration/test_faceted_search.py b/tests/test_integration/test_faceted_search.py
index de0a2b311..6ec5c44c1 100644
--- a/tests/test_integration/test_faceted_search.py
+++ b/tests/test_integration/test_faceted_search.py
@@ -99,7 +99,7 @@ class RepoSearch(FacetedSearch):
         }
 
         def search(self):
-            s = super(RepoSearch, self).search()
+            s = super().search()
             return s.filter("term", commit_repo="repo")
 
     return RepoSearch
diff --git a/tests/test_integration/test_search.py b/tests/test_integration/test_search.py
index dd68705b6..e3ce061eb 100644
--- a/tests/test_integration/test_search.py
+++ b/tests/test_integration/test_search.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 #  Licensed to Elasticsearch B.V. under one or more contributor
 #  license agreements. See the NOTICE file distributed with
 #  this work for additional information regarding copyright
@@ -16,7 +15,6 @@
 #  specific language governing permissions and limitations
 #  under the License.
 
-from __future__ import unicode_literals
 
 from elasticsearch import TransportError
 from pytest import raises
@@ -34,7 +32,7 @@ class Repository(Document):
 
     @classmethod
     def search(cls):
-        return super(Repository, cls).search().filter("term", commit_repo="repo")
+        return super().search().filter("term", commit_repo="repo")
 
     class Index:
         name = "git"
diff --git a/tests/test_result.py b/tests/test_result.py
index a1f485edc..7815bb92a 100644
--- a/tests/test_result.py
+++ b/tests/test_result.py
@@ -89,7 +89,7 @@ def test_interactive_helpers(dummy_response):
     )
 
     assert res
-    assert "<Response: %s>" % rhits == repr(res)
+    assert f"<Response: {rhits}>" == repr(res)
     assert rhits == repr(hits)
     assert {"meta", "city", "name"} == set(dir(h))
     assert "<Hit(test-index/elasticsearch): %r>" % dummy_response["hits"]["hits"][0][
diff --git a/tests/test_search.py b/tests/test_search.py
index 35395c53e..4da824182 100644
--- a/tests/test_search.py
+++ b/tests/test_search.py
@@ -195,7 +195,7 @@ def test_search_index():
     assert s._index == ["i"]
     s = s.index("i2")
     assert s._index == ["i", "i2"]
-    s = s.index(u"i3")
+    s = s.index("i3")
     assert s._index == ["i", "i2", "i3"]
     s = s.index()
     assert s._index is None
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 38caad45a..df503229f 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -89,7 +89,7 @@ def test_serializer_deals_with_Attr_versions():
 
 
 def test_serializer_deals_with_objects_with_to_dict():
-    class MyClass(object):
+    class MyClass:
         def to_dict(self):
             return 42
 
diff --git a/tests/test_validation.py b/tests/test_validation.py
index ff20b326c..328c0af48 100644
--- a/tests/test_validation.py
+++ b/tests/test_validation.py
@@ -56,7 +56,7 @@ class AutoNowDate(Date):
     def clean(self, data):
         if data is None:
             data = datetime.now()
-        return super(AutoNowDate, self).clean(data)
+        return super().clean(data)
 
 
 class Log(Document):
diff --git a/utils/license-headers.py b/utils/license-headers.py
index e28622dad..afe8d3a44 100644
--- a/utils/license-headers.py
+++ b/utils/license-headers.py
@@ -65,7 +65,7 @@ def find_files_to_fix(sources: List[str]) -> Iterator[str]:
 def does_file_need_fix(filepath: str) -> bool:
     if not filepath.endswith(".py"):
         return False
-    with open(filepath, mode="r") as f:
+    with open(filepath) as f:
         first_license_line = None
         for line in f:
             if line == license_header_lines[0]:
@@ -82,7 +82,7 @@ def does_file_need_fix(filepath: str) -> bool:
 
 
 def add_header_to_file(filepath: str) -> None:
-    with open(filepath, mode="r") as f:
+    with open(filepath) as f:
         lines = list(f)
     i = 0
     for i, line in enumerate(lines):