diff --git a/MagicFocus.hs b/MagicFocus.hs
index 444a1006..ecc10b40 100644
--- a/MagicFocus.hs
+++ b/MagicFocus.hs
@@ -7,5 +7,4 @@ magicFocus l = l { doLayout = \s -> (doLayout l) s . swap
                  , modifyLayout = \x -> fmap magicFocus `fmap` modifyLayout l x }
 
 swap :: Stack a -> Stack a
-swap Empty = Empty
-swap (Node f u d) = Node f [] (reverse u ++ d)
+swap (Stack f u d) = Stack f [] (reverse u ++ d)