1 files changed, 8 insertions, 0 deletions
diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index 7169a0f7c1..b4db670b74 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -733,6 +733,14 @@ vm_check_if_namespace(VALUE klass)
     }
 }
 
+static inline void
+vm_ensure_not_refinement_module(VALUE self)
+{
+    if (RB_TYPE_P(self, T_MODULE) && FL_TEST(self, RMODULE_IS_REFINEMENT)) {
+	rb_warn("not defined at the refinement, but at the outer class/module");
+    }
+}
+
 static inline VALUE
 vm_get_iclass(rb_control_frame_t *cfp, VALUE klass)
 {