1 files changed, 17 insertions, 0 deletions
diff --git a/testsuite/tests/gadt/T3651.hs b/testsuite/tests/gadt/T3651.hs
new file mode 100644
index 0000000000..9f671905c8
--- /dev/null
+++ b/testsuite/tests/gadt/T3651.hs
@@ -0,0 +1,17 @@
+{-# LANGUAGE GADTs #-}
+{-# LANGUAGE TypeFamilies #-}
+
+module T3651 where
+
+data Z a where
+  U :: Z ()
+  B :: Z Bool
+
+unsafe1 :: Z a -> Z a -> a
+unsafe1 B U = ()
+
+unsafe2 :: a ~ b => Z b -> Z a -> a
+unsafe2 B U = ()
+
+unsafe3 :: a ~ b => Z a -> Z b -> a
+unsafe3 B U = True