diff --git a/homotuple.cabal b/homotuple.cabal
--- a/homotuple.cabal
+++ b/homotuple.cabal
@@ -1,9 +1,9 @@
 cabal-version: 2.2
 
 name:           homotuple
-version:        0.2.1.0
+version:        0.2.1.1
 synopsis:       Homotuple, all whose elements are the same type
-description:    Homotuple, all whose elements are the same type
+description:    Homotuple, all whose elements are the same type.
 category:       Data
 homepage:       https://github.com/kakkun61/tuple
 bug-reports:    https://github.com/kakkun61/tuple/issues
diff --git a/template/Homotuple.hs b/template/Homotuple.hs
--- a/template/Homotuple.hs
+++ b/template/Homotuple.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE ConstraintKinds        #-}
+{-# LANGUAGE CPP                    #-}
 {-# LANGUAGE DataKinds              #-}
 {-# LANGUAGE FlexibleContexts       #-}
 {-# LANGUAGE FlexibleInstances      #-}
@@ -42,6 +43,10 @@
   ) where
 
 import Prelude (Num (fromInteger), error, ($), (.))
+
+#if __GLASGOW_HASKELL__ >= 904
+import Prelude (type (~))
+#endif
 
 import qualified Control.Applicative as A
 import qualified Control.Monad       as M