Index: strings/apr_strings.c
===================================================================
--- strings/apr_strings.c	(revision 774225)
+++ strings/apr_strings.c	(working copy)
@@ -55,10 +55,6 @@
 #define APR_WANT_STRFUNC
 #include "apr_want.h"
 
-#ifdef HAVE_STDDEF_H
-#include <stddef.h> /* NULL */
-#endif
-
 #ifdef HAVE_STDLIB_H
 #include <stdlib.h> /* strtol and strtoll */
 #endif
Index: include/apr.h.in
===================================================================
--- include/apr.h.in	(revision 774225)
+++ include/apr.h.in	(working copy)
@@ -87,6 +87,7 @@
 #define APR_HAVE_SEMAPHORE_H     @semaphoreh@
 #define APR_HAVE_SIGNAL_H        @signalh@
 #define APR_HAVE_STDARG_H        @stdargh@
+#define APR_HAVE_STDDEF_H        @stddefh@
 #define APR_HAVE_STDINT_H        @stdint@
 #define APR_HAVE_STDIO_H         @stdioh@
 #define APR_HAVE_STDLIB_H        @stdlibh@
@@ -123,6 +124,14 @@
 #include <winsock2.h>
 #endif
 
+/* Needed to define NULL as a pointer type.
+ * Necessary to silence gcc warnings about
+ * missing sentinels in function calls.
+ */
+#if APR_HAVE_STDDEF_H
+#include <stddef.h>
+#endif
+
 #if APR_HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
Index: configure.in
===================================================================
--- configure.in	(revision 774225)
+++ configure.in	(working copy)
@@ -1223,6 +1223,7 @@
 AC_SUBST(netinet_sctp_uioh)
 AC_SUBST(netinet_tcph)
 AC_SUBST(stdargh)
+AC_SUBST(stddefh)
 AC_SUBST(stdioh)
 AC_SUBST(stdlibh)
 AC_SUBST(stringh)