--- /dev/null
+\r
+data List a = Nil | Cons a (List a)\r
+\r
+build :: (forall l. l -> (a -> l -> l) -> l) -> List a\r
+build f = f Nil Cons\r
+\r
+main = build (\nil cons -> cons (1 :: Integer) (Cons (2 :: Integer) nil))\r
+ // ^^^^\r
+-- \r
+7:48-7:73: Expected <a> got <List Integer>.\r
+7:69-7:72: Expected <List Integer> got <a>.
\ No newline at end of file