1 files changed, 31 insertions, 0 deletions
diff --git a/testsuite/tests/polykinds/T22379a.hs b/testsuite/tests/polykinds/T22379a.hs
new file mode 100644
index 0000000000..d4caa01048
--- /dev/null
+++ b/testsuite/tests/polykinds/T22379a.hs
@@ -0,0 +1,31 @@
+{-# LANGUAGE Haskell2010 #-}
+{-# LANGUAGE PolyKinds #-}
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE TypeFamilies #-}
+module Bug where
+
+import Data.Kind
+import Data.Proxy (Proxy)
+
+data Delayed (env :: Type) (c :: Type)
+data Handler (a :: Type)
+data Router (a :: Type)
+
+-- class decl, then type decl
+
+class HasServer api where
+  type ServerT api (m :: Type -> Type) :: Type
+
+  route ::
+       Proxy api
+    -> Delayed env (Server api)
+    -> Router env
+
+  hoistServerWithContext
+      :: Proxy api
+      -> (forall x. m x -> n x)
+      -> ServerT api m
+      -> ServerT api n
+
+type Server aqi = ServerT aqi Handler
+