diff --git a/Stackage/Select.hs b/Stackage/Select.hs
index a258eda1..1a896292 100644
--- a/Stackage/Select.hs
+++ b/Stackage/Select.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE PatternGuards #-}
 module Stackage.Select
     ( select
     , defaultSelectSettings