diff --git a/deque.cabal b/deque.cabal
--- a/deque.cabal
+++ b/deque.cabal
@@ -1,7 +1,7 @@
 name:
   deque
 version:
-  0.2.1
+  0.2.2
 synopsis:
   Double-ended queue
 description:
diff --git a/library/Deque.hs b/library/Deque.hs
--- a/library/Deque.hs
+++ b/library/Deque.hs
@@ -2,6 +2,7 @@
 
 import Prelude hiding (foldr, foldr', foldl')
 import Control.Applicative
+import Control.Monad
 import Data.Foldable
 import Data.Traversable
 import Data.Maybe
@@ -163,3 +164,15 @@
     pure
   m >>= f =
     fromList (toList m >>= toList . f)
+
+instance Alternative Deque where
+  empty =
+    mempty
+  (<|>) =
+    mappend
+
+instance MonadPlus Deque where
+  mzero =
+    empty
+  mplus =
+    (<|>)