Index: src/libcfa/stdhdr/stddef.h
===================================================================
--- src/libcfa/stdhdr/stddef.h	(revision 0cf5b7992194658ccc6f30eae5069589577633a3)
+++ src/libcfa/stdhdr/stddef.h	(revision ad6cd6df0f23582ceb3b4b7e8ffea357ad0cb288)
@@ -4,7 +4,7 @@
 // The contents of this file are covered under the licence agreement in the
 // file "LICENCE" distributed with Cforall.
-// 
-// stddef.h -- 
-// 
+//
+// stddef.h --
+//
 // Author           : Peter A. Buhr
 // Created On       : Mon Jul  4 23:25:26 2016
@@ -12,8 +12,10 @@
 // Last Modified On : Tue Jul  5 20:40:01 2016
 // Update Count     : 12
-// 
+//
 
 extern "C" {
-#include_next <stddef.h>								// has internal check for multiple expansion
+#include_next <stddef.h>                // has internal check for multiple expansion
+#undef NULL
+#define NULL 0                          // define NULL as 0 rather than (void*)0 to take advantage of zero_t
 } // extern "C"