diff --git a/sip/siplib/sip.h b/sip/siplib/sip.h
index 2eb4cb43..09d2ab67 100644
--- a/sip/siplib/sip.h
+++ b/sip/siplib/sip.h
@@ -303,7 +303,7 @@ typedef unsigned int uint;
 #else
 
 /* Earlier versions of C++. */
-#define SIP_NULLPTR     0
+#define SIP_NULLPTR     NULL
 #define SIP_OVERRIDE
 
 #endif