--- a/aeson.cabal
+++ b/aeson.cabal
@@ -183,7 +183,7 @@
     UnitTests
     UnitTests.NullaryConstructors
 
-  ghc-options: -Wall -threaded -rtsopts
+  ghc-options: -Wall -threaded -rtsopts -O0
 
   build-depends:
     HUnit,
