1 files changed, 5 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/hash_with_indifferent_access.rb b/activesupport/lib/active_support/hash_with_indifferent_access.rb
index 3edeeb0029..4ff35a45a1 100644
--- a/activesupport/lib/active_support/hash_with_indifferent_access.rb
+++ b/activesupport/lib/active_support/hash_with_indifferent_access.rb
@@ -77,6 +77,11 @@ module ActiveSupport
     end
 
     def self.new_from_hash_copying_default(hash)
+      ActiveSupport::Deprecation.warn(<<-MSG.squish)
+        `ActiveSupport::HashWithIndifferentAccess.new_from_hash_copying_default`
+        has been deprecated, and will be removed in Rails 5.1. The behavior of
+        this method is now identical to the behavior of `.new`.
+      MSG
       new(hash)
     end