diff --git a/cassava.cabal b/cassava.cabal
index 5a22ccc..9723ab2 100644
--- a/cassava.cabal
+++ b/cassava.cabal
@@ -68,7 +68,6 @@ Library
     BangPatterns
     CPP
     DataKinds
-    DataKinds
     DefaultSignatures
     DeriveFunctor
     FlexibleContexts
@@ -77,7 +76,6 @@ Library
     MultiParamTypeClasses
     OverloadedStrings
     PolyKinds
-    PolyKinds
     Rank2Types
     ScopedTypeVariables
     TypeOperators