diff --git a/activesupport/lib/active_support/testing/time_helpers.rb b/activesupport/lib/active_support/testing/time_helpers.rb
index 84cbdf9608e6e3e688e2c08da2d8071b900a2399..0ee6332d6f283353e28d77e82f60888c3eb7d0ea 100644
--- a/activesupport/lib/active_support/testing/time_helpers.rb
+++ b/activesupport/lib/active_support/testing/time_helpers.rb
@@ -23,7 +23,7 @@ def stub_object(object, method_name, return_value)
       end
 
       def unstub_all!
-        @stubs.each do |_, stub|
+        @stubs.each_value do |stub|
           unstub_object(stub)
         end
         @stubs = {}