diff --git a/test/Data/Adjoined/Spec.hs b/test/Data/Adjoined/Spec.hs
index 7433e0721..be4780450 100644
--- a/test/Data/Adjoined/Spec.hs
+++ b/test/Data/Adjoined/Spec.hs
@@ -6,3 +6,6 @@ import Test.QuickCheck
 
 instance Arbitrary a => Arbitrary (Adjoined a) where
   arbitrary = fromList <$> arbitrary
+
+newtype Separated a = Separated { unSeparated :: a }
+  deriving (Eq, Functor, Show)