Default impls
diff --git a/tests/cases/traits.rs b/tests/cases/traits.rs
index 09ee72c..7f24463 100644
--- a/tests/cases/traits.rs
+++ b/tests/cases/traits.rs
@@ -32,3 +32,5 @@
     mac!();
     mac!{}
 }
+
+impl T::U for .. {}