Index: src/libcfa/stdhdr/stddef.h
===================================================================
--- src/libcfa/stdhdr/stddef.h	(revision d6c1dd090f5cc5c9517502585fa1dc26b90e9a6d)
+++ src/libcfa/stdhdr/stddef.h	(revision a16a7ec109d1594fead1ef7ddda3af85ec3b572b)
@@ -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"