diff --git a/ghc/compiler/main/MkIface.lhs b/ghc/compiler/main/MkIface.lhs
index 5ec45f18fec8dd17846891e351ca8e9143643a61..adf89db91481e5a8ace55cfb821338b8bc094634 100644
--- a/ghc/compiler/main/MkIface.lhs
+++ b/ghc/compiler/main/MkIface.lhs
@@ -447,7 +447,7 @@ mkFinalId codegen_ids is_rec id rhs
     bottoming_fn   = isBottomingStrictness (strictnessInfo core_idinfo)
 
     unfolding    = mkTopUnfolding rhs
-    rhs_is_small = neverUnfold unfolding
+    rhs_is_small = not (neverUnfold unfolding)
 
     unfold_info | show_unfold = unfolding
 		| otherwise   = noUnfolding