diff --git a/src/Test/QuickCheck/Arbitrary.hs b/src/Test/QuickCheck/Arbitrary.hs
index b2d468c4..94aec03f 100644
--- a/src/Test/QuickCheck/Arbitrary.hs
+++ b/src/Test/QuickCheck/Arbitrary.hs
@@ -409,7 +409,7 @@ instance GSubtermsIncl f a => GSubtermsIncl (M1 i c f) a where
 instance OVERLAPPING_ GSubtermsIncl (K1 i a) a where
   gSubtermsIncl (K1 x) = [x]
 
-instance OVERLAPPING_ GSubtermsIncl (K1 i a) b where
+instance GSubtermsIncl (K1 i a) b where
   gSubtermsIncl (K1 _) = []
 
 #endif