diff --git a/hepdata/modules/records/utils/submission.py b/hepdata/modules/records/utils/submission.py
index d38fc77ea..094ff23d2 100644
--- a/hepdata/modules/records/utils/submission.py
+++ b/hepdata/modules/records/utils/submission.py
@@ -58,11 +58,7 @@
 from sqlalchemy.orm.exc import NoResultFound
 from sqlalchemy.exc import SQLAlchemyError
 import yaml
-
-try:
-    from yaml import CSafeLoader as Loader
-except ImportError: #pragma: no cover
-    from yaml import SafeLoader as Loader #pragma: no cover
+from yaml import CSafeLoader as Loader
 
 def construct_yaml_str(self, node):
     # Override the default string handling function
@@ -70,8 +66,6 @@ def construct_yaml_str(self, node):
     return self.construct_scalar(node)
 Loader.add_constructor(u'tag:yaml.org,2002:str', construct_yaml_str)
 
-from urllib.error import URLError
-
 logging.basicConfig()
 log = logging.getLogger(__name__)
 
diff --git a/hepdata/modules/records/utils/yaml_utils.py b/hepdata/modules/records/utils/yaml_utils.py
index 2707c984c..bab95280f 100644
--- a/hepdata/modules/records/utils/yaml_utils.py
+++ b/hepdata/modules/records/utils/yaml_utils.py
@@ -30,10 +30,7 @@
 from hepdata.modules.records.utils.data_processing_utils import str_presenter
 import shutil
 import yaml
-try:
-    from yaml import CSafeLoader as Loader, CSafeDumper as Dumper
-except ImportError: #pragma: no cover
-    from yaml import SafeLoader as Loader, SafeDumper as Dumper #pragma: no cover
+from yaml import CSafeLoader as Loader, CSafeDumper as Dumper
 import zipfile
 from datetime import datetime
 from dateutil.parser import parse
diff --git a/hepdata/modules/records/views.py b/hepdata/modules/records/views.py
index 731476894..d91822577 100644
--- a/hepdata/modules/records/views.py
+++ b/hepdata/modules/records/views.py
@@ -34,10 +34,7 @@
 from flask_security.utils import verify_password
 from sqlalchemy import or_, func
 import yaml
-try:
-    from yaml import CBaseLoader as Loader
-except ImportError:  # pragma: no cover
-    from yaml import BaseLoader as Loader  # pragma: no cover
+from yaml import CBaseLoader as Loader
 
 from hepdata.config import CFG_DATA_TYPE, CFG_PUB_TYPE, SITE_URL
 from hepdata.ext.elasticsearch.api import get_records_matching_field, get_count_for_collection, get_n_latest_records, \
diff --git a/hepdata/version.py b/hepdata/version.py
index 12226ba53..b361fbf2e 100644
--- a/hepdata/version.py
+++ b/hepdata/version.py
@@ -28,4 +28,4 @@
 and parsed by ``setup.py``.
 """
 
-__version__ = "0.9.4dev20210218"
+__version__ = "0.9.4dev20210224"
diff --git a/requirements.txt b/requirements.txt
index 8513d0fc5..7fd4b1b3d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -40,6 +40,7 @@ lxml==4.6.2
 msgpack==0.6.2
 psycopg2-binary==2.8.4
 python-dateutil==2.8.1
+pyyaml==5.4.1
 requests==2.23.0
 requests-oauthlib==1.1.0   # Indirect ('invenio-oauthclient' problem)
 responses==0.10.9
diff --git a/tests/pyyaml_test.py b/tests/pyyaml_test.py
new file mode 100644
index 000000000..0d6b3caf7
--- /dev/null
+++ b/tests/pyyaml_test.py
@@ -0,0 +1,50 @@
+# -*- coding: utf-8 -*-
+#
+# This file is part of HEPData.
+# Copyright (C) 2021 CERN.
+#
+# HEPData is free software; you can redistribute it
+# and/or modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of the
+# License, or (at your option) any later version.
+#
+# HEPData is distributed in the hope that it will be
+# useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with HEPData; if not, write to the
+# Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307, USA.
+#
+# In applying this license, CERN does not
+# waive the privileges and immunities granted to it by virtue of its status
+# as an Intergovernmental Organization or submit itself to any jurisdiction.
+
+import pytest
+import yaml
+
+
+def test_parse_trailing_tab_libyaml():
+    """
+    Check that PyYAML (with LibYAML) can parse a trailing tab character.
+    Currently this is only possible with LibYAML, not with pure-Python PyYAML.
+
+    :return:
+    """
+
+    data = yaml.load('key: value\t', Loader=yaml.CSafeLoader)
+    assert data['key'] == 'value'
+
+
+def test_parse_trailing_tab_pyyaml():
+    """
+    Latest PyYAML v5.4.1 (pure Python) currently has a bug parsing a trailing tab character.
+    https://github.com/yaml/pyyaml/issues/306 and https://github.com/yaml/pyyaml/issues/450
+
+    :return:
+    """
+
+    with pytest.raises(yaml.scanner.ScannerError):
+        yaml.load('key: value\t', Loader=yaml.SafeLoader)
diff --git a/tests/records_test.py b/tests/records_test.py
index c725eb161..34201c7be 100644
--- a/tests/records_test.py
+++ b/tests/records_test.py
@@ -124,7 +124,7 @@ def test_has_role(app):
 def test_data_processing(app):
     base_dir = os.path.dirname(os.path.realpath(__file__))
 
-    data = yaml.safe_load(open(os.path.join(base_dir, 'test_data/data_table.yaml'), 'rt'))
+    data = yaml.load(open(os.path.join(base_dir, 'test_data/data_table.yaml'), 'rt'), Loader=yaml.CSafeLoader)
 
     assert ('independent_variables' in data)
     assert ('dependent_variables' in data)