diff --git a/testsuite/tests/polykinds/PolyKinds06.hs b/testsuite/tests/polykinds/PolyKinds06.hs
index 9691d45ebb0dd332284000de60894c67d5e4ee3f..691d103d6f01cfe0575e7c28d68c97d9137fa554 100644
--- a/testsuite/tests/polykinds/PolyKinds06.hs
+++ b/testsuite/tests/polykinds/PolyKinds06.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE DataKinds                  #-}
+{-# LANGUAGE DataKinds, KindSignatures  #-}
 {-# LANGUAGE GADTs                      #-}
 
 module PolyKinds06 where