1 files changed, 9 insertions, 0 deletions
diff --git a/actionpack/test/controller/parameters/mutators_test.rb b/actionpack/test/controller/parameters/mutators_test.rb
index 312b1e5b27..31ee7964f5 100644
--- a/actionpack/test/controller/parameters/mutators_test.rb
+++ b/actionpack/test/controller/parameters/mutators_test.rb
@@ -118,4 +118,13 @@ class ParametersMutatorsTest < ActiveSupport::TestCase
   test "transform_values! retains unpermitted status" do
     assert_not_predicate @params.transform_values! { |v| v }, :permitted?
   end
+
+  test "deep_transform_keys! retains permitted status" do
+    @params.permit!
+    assert_predicate @params.deep_transform_keys! { |k| k }, :permitted?
+  end
+
+  test "deep_transform_keys! retains unpermitted status" do
+    assert_not_predicate @params.deep_transform_keys! { |k| k }, :permitted?
+  end
 end