Index: b/concurrent-supply.cabal
===================================================================
--- a/concurrent-supply.cabal
+++ b/concurrent-supply.cabal
@@ -43,7 +43,7 @@ test-suite properties
   type: exitcode-stdio-1.0
   main-is: properties.hs
   default-language: Haskell2010
-  ghc-options: -w -threaded -rtsopts -with-rtsopts=-N
+  ghc-options: -w -threaded -rtsopts
   hs-source-dirs: test
 
   if !flag(test-properties)
