diff --git a/keys.cabal b/keys.cabal
--- a/keys.cabal
+++ b/keys.cabal
@@ -1,6 +1,6 @@
 name:          keys
 category:      Data Structures, Containers
-version:       3.0.2
+version:       3.0.3
 license:       BSD3
 cabal-version: >= 1.6
 license-file:  LICENSE
diff --git a/src/Data/Key.hs b/src/Data/Key.hs
--- a/src/Data/Key.hs
+++ b/src/Data/Key.hs
@@ -1,4 +1,8 @@
 {-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE CPP #-}
+#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 702
+{-# LANGUAGE Trustworthy #-}
+#endif
 module Data.Key (
   -- * Keys
     Key