1 files changed, 20 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_compile/T19044.hs b/testsuite/tests/typecheck/should_compile/T19044.hs
new file mode 100644
index 0000000000..ced7658582
--- /dev/null
+++ b/testsuite/tests/typecheck/should_compile/T19044.hs
@@ -0,0 +1,20 @@
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+module T19044 where
+
+class C a b where
+  m :: a -> b
+
+instance C a a where
+  m = id
+
+instance C a (Maybe a) where
+  m _ = Nothing
+
+f :: a -> Maybe a
+f = g
+  where
+    g x = h (m x) x
+
+h :: Maybe a -> a -> Maybe a
+h = const