1 files changed, 16 insertions, 0 deletions
diff --git a/testsuite/tests/gadt/T18191.hs b/testsuite/tests/gadt/T18191.hs
new file mode 100644
index 0000000000..e30c7ad5b1
--- /dev/null
+++ b/testsuite/tests/gadt/T18191.hs
@@ -0,0 +1,16 @@
+{-# LANGUAGE GADTs #-}
+{-# LANGUAGE RankNTypes #-}
+module T18191 where
+
+data T where
+  MkT :: (forall a. a -> b -> T)
+
+data S a where
+  MkS :: (forall a. S a)
+
+data U a where
+  MkU :: (Show a => U a)
+
+data Z a where
+  MkZ1 :: forall a. forall b. { unZ1 :: (a, b) } -> Z (a, b)
+  MkZ2 :: Eq a => Eq b => { unZ1 :: (a, b) } -> Z (a, b)