diff --git a/activesupport/lib/active_support/core_ext/object/json.rb b/activesupport/lib/active_support/core_ext/object/json.rb
index a65e273236..8ba694266d 100644
--- a/activesupport/lib/active_support/core_ext/object/json.rb
+++ b/activesupport/lib/active_support/core_ext/object/json.rb
@@ -19,8 +19,7 @@ require "active_support/core_ext/date/conversions"
 # The JSON gem adds a few modules to Ruby core classes containing :to_json definition, overwriting
 # their default behavior. That said, we need to define the basic to_json method in all of them,
 # otherwise they will always use to_json gem implementation, which is backwards incompatible in
-# several cases (for instance, the JSON implementation for Hash does not work) with inheritance
-# and consequently classes as ActiveSupport::OrderedHash cannot be serialized to json.
+# several cases (for instance, the JSON implementation for Hash does not work) with inheritance.
 #
 # On the other hand, we should avoid conflict with ::JSON.{generate,dump}(obj). Unfortunately, the
 # JSON gem's encoder relies on its own to_json implementation to encode objects. Since it always
diff --git a/activesupport/test/core_ext/hash_ext_test.rb b/activesupport/test/core_ext/hash_ext_test.rb
index 3c6263c830..7c2500dd4f 100644
--- a/activesupport/test/core_ext/hash_ext_test.rb
+++ b/activesupport/test/core_ext/hash_ext_test.rb
@@ -4,7 +4,6 @@ require_relative "../abstract_unit"
 require "active_support/core_ext/hash"
 require "bigdecimal"
 require "active_support/core_ext/string/access"
-require "active_support/ordered_hash"
 require "active_support/core_ext/object/conversions"
 require "active_support/core_ext/date/conversions"
 require "active_support/core_ext/object/deep_dup"
diff --git a/activesupport/test/core_ext/object/to_query_test.rb b/activesupport/test/core_ext/object/to_query_test.rb
index 3f70767997..21f97cc3fd 100644
--- a/activesupport/test/core_ext/object/to_query_test.rb
+++ b/activesupport/test/core_ext/object/to_query_test.rb
@@ -1,7 +1,6 @@
 # frozen_string_literal: true
 
 require_relative "../../abstract_unit"
-require "active_support/ordered_hash"
 require "active_support/core_ext/object/to_query"
 require "active_support/core_ext/string/output_safety"
 
diff --git a/activesupport/test/hash_with_indifferent_access_test.rb b/activesupport/test/hash_with_indifferent_access_test.rb
index b42116cab9..fbb4fb9715 100644
--- a/activesupport/test/hash_with_indifferent_access_test.rb
+++ b/activesupport/test/hash_with_indifferent_access_test.rb
@@ -4,7 +4,6 @@ require_relative "abstract_unit"
 require "active_support/core_ext/hash"
 require "bigdecimal"
 require "active_support/core_ext/string/access"
-require "active_support/ordered_hash"
 require "active_support/core_ext/object/conversions"
 require "active_support/core_ext/object/deep_dup"
 require "active_support/inflections"
diff --git a/guides/source/active_support_core_extensions.md b/guides/source/active_support_core_extensions.md
index 41c9959705..9ab9fba318 100644
--- a/guides/source/active_support_core_extensions.md
+++ b/guides/source/active_support_core_extensions.md
@@ -446,7 +446,7 @@ NOTE: Defined in `active_support/core_ext/object/with_options.rb`.
 
 ### JSON support
 
-Active Support provides a better implementation of `to_json` than the `json` gem ordinarily provides for Ruby objects. This is because some classes, like `Hash`, `OrderedHash` and `Process::Status` need special handling in order to provide a proper JSON representation.
+Active Support provides a better implementation of `to_json` than the `json` gem ordinarily provides for Ruby objects. This is because some classes, like `Hash` and `Process::Status` need special handling in order to provide a proper JSON representation.
 
 NOTE: Defined in `active_support/core_ext/object/json.rb`.