diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index a94ecd7a..b74ee513 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -42,11 +42,17 @@ jobs:
       - lint
     strategy:
       matrix:
-        rails: ['5.2', '6.0.4', '6.1']
-        ruby: ['2.6', '2.7', '3.0']
+        rails: ['5.2', '6.0.4', '6.1', '7.0']
+        ruby: ['2.6', '2.7', '3.0', '3.1']
         exclude:
           - rails: '5.2'
             ruby: '3.0'
+          - rails: '5.2'
+            ruby: '3.1'
+          - rails: '7.0'
+            ruby: '2.6'
+          - rails: '7.0'
+            ruby: '2.7'
     runs-on: ubuntu-latest
     env:
       RAILS_VERSION: ${{ matrix.rails }}
diff --git a/lib/ice_cube/parsers/yaml_parser.rb b/lib/ice_cube/parsers/yaml_parser.rb
index 9810b797..2b979811 100644
--- a/lib/ice_cube/parsers/yaml_parser.rb
+++ b/lib/ice_cube/parsers/yaml_parser.rb
@@ -7,7 +7,7 @@ class YamlParser < HashParser
     attr_reader :hash
 
     def initialize(yaml)
-      @hash = YAML.load(yaml)
+      @hash = YAML.safe_load(yaml, permitted_classes: [Date, Symbol, Time], aliases: true)
       yaml.match SERIALIZED_START do |match|
         start_time = hash[:start_time] || hash[:start_date]
         TimeUtil.restore_deserialized_offset start_time, match[:tz]
diff --git a/lib/ice_cube/rule.rb b/lib/ice_cube/rule.rb
index 726ce17f..6652c3db 100644
--- a/lib/ice_cube/rule.rb
+++ b/lib/ice_cube/rule.rb
@@ -42,7 +42,7 @@ def to_yaml(*args)
 
     # From yaml
     def self.from_yaml(yaml)
-      from_hash YAML.load(yaml)
+      from_hash YAML.safe_load(yaml, permitted_classes: [Date, Symbol, Time])
     end
 
     def to_hash
diff --git a/spec/examples/active_support_spec.rb b/spec/examples/active_support_spec.rb
index a07a9081..51973415 100644
--- a/spec/examples/active_support_spec.rb
+++ b/spec/examples/active_support_spec.rb
@@ -1,4 +1,5 @@
 require File.dirname(__FILE__) + "/../spec_helper"
+require "active_support"
 require "active_support/time"
 require "active_support/version"
 require "tzinfo" if ActiveSupport::VERSION::MAJOR == 3
@@ -45,10 +46,10 @@ module IceCube
     end
 
     it "can round trip TimeWithZone to YAML" do
-      schedule = Schedule.new(t0 = Time.zone.parse("2010-02-05 05:00:00"))
-      schedule.add_recurrence_time t0
-      schedule2 = Schedule.from_yaml(schedule.to_yaml)
-      expect(schedule.all_occurrences).to eq(schedule2.all_occurrences)
+      schedule1 = Schedule.new(t0 = Time.zone.parse("2010-02-05 05:00:00"))
+      schedule1.add_recurrence_time t0
+      schedule2 = Schedule.from_yaml(schedule1.to_yaml)
+      expect(schedule2.all_occurrences).to eq(schedule1.all_occurrences)
     end
 
     it "uses local zone from start time to determine occurs_on? from the beginning of day" do
diff --git a/spec/examples/serialization_spec.rb b/spec/examples/serialization_spec.rb
index 7886a04a..5583c23b 100644
--- a/spec/examples/serialization_spec.rb
+++ b/spec/examples/serialization_spec.rb
@@ -15,7 +15,7 @@
       let(:start_time) { Time.now.in_time_zone("America/Vancouver") }
 
       it "serializes time as a Hash" do
-        hash = YAML.load(yaml)
+        hash = YAML.safe_load(yaml, permitted_classes: [Symbol, Time])
         expect(hash[:start_time][:time]).to eq start_time.utc
         expect(hash[:start_time][:zone]).to eq "America/Vancouver"
       end
diff --git a/spec/examples/to_ical_spec.rb b/spec/examples/to_ical_spec.rb
index 7ee59236..39dd5209 100644
--- a/spec/examples/to_ical_spec.rb
+++ b/spec/examples/to_ical_spec.rb
@@ -1,4 +1,5 @@
 require File.dirname(__FILE__) + "/../spec_helper"
+require "active_support"
 require "active_support/time"
 
 describe IceCube, "to_ical" do
diff --git a/spec/examples/to_yaml_spec.rb b/spec/examples/to_yaml_spec.rb
index f8fcade9..e7c62c59 100644
--- a/spec/examples/to_yaml_spec.rb
+++ b/spec/examples/to_yaml_spec.rb
@@ -78,14 +78,15 @@ module IceCube
     end
 
     it "should be able to make a round-trip to YAML with .day_of_year" do
-      schedule = Schedule.new(Time.now)
-      schedule.add_recurrence_rule Rule.yearly.day_of_year(100, 200)
+      schedule1 = Schedule.new(Time.now)
+      schedule1.add_recurrence_rule Rule.yearly.day_of_year(100, 200)
 
-      yaml_string = schedule.to_yaml
+      yaml_string = schedule1.to_yaml
       schedule2 = Schedule.from_yaml(yaml_string)
 
       # compare without usecs
-      expect(schedule.first(10).map { |r| r.to_s }).to eq(schedule2.first(10).map { |r| r.to_s })
+      expect(schedule2.first(10).map { |r| r.to_s })
+        .to eq(schedule1.first(10).map { |r| r.to_s })
     end
 
     it "should be able to make a round-trip to YAML with .hour_of_day" do
@@ -184,7 +185,7 @@ module IceCube
       schedule2 = Schedule.from_yaml(schedule1.to_yaml) # round trip
 
       end_time = Time.now + ONE_DAY
-      expect(schedule1.occurrences(end_time)).to eq(schedule2.occurrences(end_time))
+      expect(schedule2.occurrences(end_time)).to eq(schedule1.occurrences(end_time))
     end
 
     it "should be able to make a round trip with an exception time" do
@@ -323,7 +324,8 @@ module IceCube
 
       symbol_yaml = Schedule.from_hash(symbol_data).to_yaml
       string_yaml = Schedule.from_hash(string_data).to_yaml
-      expect(YAML.load(symbol_yaml)).to eq(YAML.load(string_yaml))
+      expect(YAML.safe_load(symbol_yaml, permitted_classes: [Symbol, Time]))
+        .to eq(YAML.safe_load(string_yaml, permitted_classes: [Symbol, Time]))
     end
 
     it "should raise an ArgumentError when trying to deserialize an invalid rule type" do