diff --git a/List.cabal b/List.cabal
--- a/List.cabal
+++ b/List.cabal
@@ -1,5 +1,5 @@
 Name:                List
-Version:             0.5.1
+Version:             0.5.2
 Category:            Control
 Synopsis:            List monad transformer and class
 Description:
diff --git a/src/Control/Monad/Trans/List.hs b/src/Control/Monad/Trans/List.hs
--- a/src/Control/Monad/Trans/List.hs
+++ b/src/Control/Monad/Trans/List.hs
@@ -20,7 +20,7 @@
 
 import Data.List.Class (List(..), ListItem(..), foldrL)
 
-import Control.Applicative (Applicative(..))
+import Control.Applicative
 import Control.Monad (MonadPlus(..), ap, liftM)
 import Control.Monad.IO.Class (MonadIO(..))
 import Control.Monad.Trans.Class (MonadTrans(..))
@@ -59,6 +59,10 @@
 instance Monad m => MonadPlus (ListT m) where
     mzero = mempty
     mplus = mappend
+
+instance Monad m => Alternative (ListT m) where
+    (<|>) = mplus
+    empty = mzero
 
 instance MonadTrans ListT where
     lift = ListT . liftM (`Cons` mempty)