1 files changed, 26 insertions, 0 deletions
diff --git a/testsuite/tests/polykinds/T15170.hs b/testsuite/tests/polykinds/T15170.hs
new file mode 100644
index 0000000000..02de90ae12
--- /dev/null
+++ b/testsuite/tests/polykinds/T15170.hs
@@ -0,0 +1,26 @@
+{-# LANGUAGE AllowAmbiguousTypes #-}
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE DataKinds, PolyKinds #-}
+{-# LANGUAGE TypeOperators #-}
+module T15170  where
+
+import Data.Kind
+import Data.Proxy
+
+data TyFun :: Type -> Type -> Type
+type a ~> b = TyFun a b -> Type
+infixr 0 ~>
+
+type family Apply (f :: k1 ~> k2) (x :: k1) :: k2
+type f @@ x = Apply f x
+infixl 9 @@
+
+wat :: forall (a :: Type)
+              (b :: a ~> Type)
+              (c :: forall (x :: a). Proxy x ~> b @@ x ~> Type)
+              (f :: forall (x :: a) (y :: b @@ x). Proxy x ~> Proxy y ~> c @@ ('Proxy :: Proxy x) @@ y)
+              (x :: a).
+      (forall (xx :: a) (yy :: b @@ xx). Proxy (f @@ ('Proxy :: Proxy xx) @@ ('Proxy :: Proxy yy)))
+   -> ()
+wat _ = ()