diff --git a/libs/sigc++2/sigc++/functors/functor_trait.h b/libs/sigc++2/sigc++/functors/functor_trait.h
index 656d010414..5a9ff8f42e 100644
--- a/libs/sigc++2/sigc++/functors/functor_trait.h
+++ b/libs/sigc++2/sigc++/functors/functor_trait.h
@@ -24,6 +24,10 @@
 #define _SIGC_FUNCTORS_MACROS_FUNCTOR_TRAITHM4_
 #include <sigc++/type_traits.h>
 
+#ifdef nil
+/* stupid OS X, defining nil */
+#undef nil
+#endif
 
 namespace sigc {