diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index 0f94d1e67e035bef66ab817792f143ddcb8f946c..89b3fb87827c954073a3e44f3798fd66afdc38b3 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,3 +1,8 @@
+*   Remove deprecated `active_support/core_ext/big_decimal/yaml_conversions`
+    file.
+
+    *Rafael Mendonça França*
+
 *   Remove deprecated methods `ActiveSupport::Cache::Store.instrument` and
     `ActiveSupport::Cache::Store.instrument=`.
 
diff --git a/activesupport/lib/active_support/core_ext/big_decimal/yaml_conversions.rb b/activesupport/lib/active_support/core_ext/big_decimal/yaml_conversions.rb
deleted file mode 100644
index 46ba93ead4c9d904d6517ef5fc69f889b015950c..0000000000000000000000000000000000000000
--- a/activesupport/lib/active_support/core_ext/big_decimal/yaml_conversions.rb
+++ /dev/null
@@ -1,14 +0,0 @@
-ActiveSupport::Deprecation.warn 'core_ext/big_decimal/yaml_conversions is deprecated and will be removed in the future.'
-
-require 'bigdecimal'
-require 'yaml'
-require 'active_support/core_ext/big_decimal/conversions'
-
-class BigDecimal
-  YAML_MAPPING = { 'Infinity' => '.Inf', '-Infinity' => '-.Inf', 'NaN' => '.NaN' }
-
-  def encode_with(coder)
-    string = to_s
-    coder.represent_scalar(nil, YAML_MAPPING[string] || string)
-  end
-end
diff --git a/activesupport/test/core_ext/big_decimal/yaml_conversions_test.rb b/activesupport/test/core_ext/big_decimal/yaml_conversions_test.rb
deleted file mode 100644
index e634679d2012b58fafdb19d1b8753558b42a44be..0000000000000000000000000000000000000000
--- a/activesupport/test/core_ext/big_decimal/yaml_conversions_test.rb
+++ /dev/null
@@ -1,11 +0,0 @@
-require 'abstract_unit'
-
-class BigDecimalYamlConversionsTest < ActiveSupport::TestCase
-  def test_to_yaml
-    assert_deprecated { require 'active_support/core_ext/big_decimal/yaml_conversions' }
-    assert_match("--- 100000.30020320320000000000000000000000000000001\n", BigDecimal.new('100000.30020320320000000000000000000000000000001').to_yaml)
-    assert_match("--- .Inf\n",  BigDecimal.new('Infinity').to_yaml)
-    assert_match("--- .NaN\n",  BigDecimal.new('NaN').to_yaml)
-    assert_match("--- -.Inf\n", BigDecimal.new('-Infinity').to_yaml)
-  end
-end