1 files changed, 24 insertions, 0 deletions
diff --git a/testsuite/tests/pmcheck/should_compile/T18533.hs b/testsuite/tests/pmcheck/should_compile/T18533.hs
new file mode 100644
index 0000000000..3b4fdf8b89
--- /dev/null
+++ b/testsuite/tests/pmcheck/should_compile/T18533.hs
@@ -0,0 +1,24 @@
+{-# OPTIONS_GHC -Wincomplete-patterns -fforce-recomp #-}
+{-# LANGUAGE GADTs, DataKinds, TypeFamilies, BangPatterns #-}
+
+module T18533 where
+
+data SBool (b :: Bool) where
+  STrue  :: SBool 'True
+  SFalse :: SBool 'False
+
+type family Fam (b :: Bool)
+type instance Fam 'True = T
+
+data T = T Bool
+
+f :: Fam b -> SBool b -> Bool
+f !t s = case s of
+    STrue -> a where a = case t of T a -> a
+    _     -> False
+
+
+g :: Bool -> Bool
+g x = case x of
+  True -> a where a = case x of True -> False
+  False -> True