diff --git a/activerecord/lib/active_record/attribute_set.rb b/activerecord/lib/active_record/attribute_set.rb
index 5be11e6ab9..8a964fb03c 100644
--- a/activerecord/lib/active_record/attribute_set.rb
+++ b/activerecord/lib/active_record/attribute_set.rb
@@ -13,11 +13,11 @@ module ActiveRecord
     end
 
     def values_before_type_cast
-      attributes.each_with_object({}) { |(k, v), h| h[k] = v.value_before_type_cast }
+      attributes.transform_values(&:value_before_type_cast)
     end
 
     def to_hash
-      initialized_attributes.each_with_object({}) { |(k, v), h| h[k] = v.value }
+      initialized_attributes.transform_values(&:value)
     end
     alias_method :to_h, :to_hash
 
@@ -43,11 +43,7 @@ module ActiveRecord
     end
 
     def initialize_dup(_)
-      @attributes = attributes.dup
-      attributes.each do |key, attr|
-        attributes[key] = attr.dup
-      end
-
+      @attributes = attributes.transform_values(&:dup)
       super
     end
 
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 662c99269e..32e7c50588 100644
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -9,6 +9,7 @@ require 'active_support/core_ext/class/delegating_attributes'
 require 'active_support/core_ext/array/extract_options'
 require 'active_support/core_ext/hash/deep_merge'
 require 'active_support/core_ext/hash/slice'
+require 'active_support/core_ext/hash/transform_values'
 require 'active_support/core_ext/string/behavior'
 require 'active_support/core_ext/kernel/singleton_class'
 require 'active_support/core_ext/module/introspection'