diff --git a/src/Waterdeep/Types.hs b/src/Waterdeep/Types.hs
index 20be86a..4899cd7 100644
--- a/src/Waterdeep/Types.hs
+++ b/src/Waterdeep/Types.hs
@@ -312,9 +312,13 @@ instance Monad Waterdeep where
    (Waterdeep m) >>= f = Waterdeep (m >>= unWaterdeep . f)
    fail = Waterdeep . fail
 
+instance Alternative Waterdeep where
+   empty = Waterdeep empty
+   Waterdeep m <|> Waterdeep n = Waterdeep (m <|> n)
+
 instance MonadPlus Waterdeep where
-   mzero = Waterdeep mzero
-   (Waterdeep m) `mplus` (Waterdeep n) = Waterdeep (m `mplus` n)
+   mzero = empty
+   mplus = (<|>)
 
 instance MonadState WaterdeepState Waterdeep where
    state = Waterdeep . lift . state