diff --git a/test/ruby/test_pattern_matching.rb b/test/ruby/test_pattern_matching.rb
index bba83f662e..988a9dfe39 100644
--- a/test/ruby/test_pattern_matching.rb
+++ b/test/ruby/test_pattern_matching.rb
@@ -1033,7 +1033,7 @@ END
     assert_block do
       case {}
       in {}
-        $keys == nil
+        C.keys == nil
       end
     end