Index: grep-2.5.4/src/search.c
===================================================================
--- grep-2.5.4.orig/src/search.c
+++ grep-2.5.4/src/search.c
@@ -34,6 +34,8 @@
 #include "system.h"
 #include "grep.h"
 #ifndef FGREP_PROGRAM
+#include <stdio.h>
+#define __USE_GNU
 # include <regex.h>
 # include "dfa.h"
 #endif
@@ -45,6 +47,7 @@
 #endif
 #include "mbchar.h"
 
+
 #define NCHAR (UCHAR_MAX + 1)
 
 /* For -w, we also consider _ to be word constituent.  */
Index: grep-2.5.4/src/dfa.c
===================================================================
--- grep-2.5.4.orig/src/dfa.c
+++ grep-2.5.4/src/dfa.c
@@ -120,6 +120,7 @@ extern void free();
 # include <wctype.h>
 #endif
 
+#define __USE_GNU
 #include "regex.h"
 #include "dfa.h"
 #include "hard-locale.h"