diff --git a/Data/EnumMap/Base.hs b/Data/EnumMap/Base.hs
index f7630db..101e080 100644
--- a/Data/EnumMap/Base.hs
+++ b/Data/EnumMap/Base.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE DeriveDataTypeable         #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE DeriveTraversable          #-}
 
 -- |
 -- Module      :  $Header$