diff --git a/gnu/usr.bin/grep/Makefile b/gnu/usr.bin/grep/Makefile
index c8d491588091..a7811a3c656c 100644
--- a/gnu/usr.bin/grep/Makefile
+++ b/gnu/usr.bin/grep/Makefile
@@ -1,5 +1,5 @@
 PROG=	grep
-SRCS=	dfa.c grep.c getopt.c kwset.c obstack.c regex.c search.c
+SRCS=   dfa.c grep.c getopt.c kwset.c obstack.c search.c
 CFLAGS+=-DGREP -DHAVE_STRING_H=1 -DHAVE_SYS_PARAM_H=1 -DHAVE_UNISTD_H=1 \
 	-DHAVE_GETPAGESIZE=1 -DHAVE_MEMCHR=1 -DHAVE_STRERROR=1 \
 	-DHAVE_VALLOC=1
@@ -8,6 +8,9 @@ LINKS+= ${BINDIR}/grep ${BINDIR}/egrep \
 	${BINDIR}/grep ${BINDIR}/fgrep
 MLINKS= grep.1 egrep.1 grep.1 fgrep.1
 
+DPADD+= ${LIBGNUREGEX}
+LDADD+= -lgnuregex
+
 check:	all
 	sh ${.CURDIR}/tests/check.sh ${.CURDIR}/tests
 
diff --git a/gnu/usr.bin/grep/dfa.c b/gnu/usr.bin/grep/dfa.c
index fc649af0cbe5..4a02d0d953c2 100644
--- a/gnu/usr.bin/grep/dfa.c
+++ b/gnu/usr.bin/grep/dfa.c
@@ -42,19 +42,6 @@ extern void free();
 #define isgraph(C) (isprint(C) && !isspace(C))
 #endif
 
-#ifdef isascii
-#define ISALPHA(C) (isascii(C) && isalpha(C))
-#define ISUPPER(C) (isascii(C) && isupper(C))
-#define ISLOWER(C) (isascii(C) && islower(C))
-#define ISDIGIT(C) (isascii(C) && isdigit(C))
-#define ISXDIGIT(C) (isascii(C) && isxdigit(C))
-#define ISSPACE(C) (isascii(C) && isspace(C))
-#define ISPUNCT(C) (isascii(C) && ispunct(C))
-#define ISALNUM(C) (isascii(C) && isalnum(C))
-#define ISPRINT(C) (isascii(C) && isprint(C))
-#define ISGRAPH(C) (isascii(C) && isgraph(C))
-#define ISCNTRL(C) (isascii(C) && iscntrl(C))
-#else
 #define ISALPHA(C) isalpha(C)
 #define ISUPPER(C) isupper(C)
 #define ISLOWER(C) islower(C)
@@ -66,10 +53,9 @@ extern void free();
 #define ISPRINT(C) isprint(C)
 #define ISGRAPH(C) isgraph(C)
 #define ISCNTRL(C) iscntrl(C)
-#endif
 
 #include "dfa.h"
-#include "regex.h"
+#include "gnuregex.h"
 
 #if __STDC__
 typedef void *ptr_t;
diff --git a/gnu/usr.bin/grep/search.c b/gnu/usr.bin/grep/search.c
index d2be489f5757..43c2d1262fa8 100644
--- a/gnu/usr.bin/grep/search.c
+++ b/gnu/usr.bin/grep/search.c
@@ -59,7 +59,7 @@ extern char *memchr();
 #include "grep.h"
 #include "dfa.h"
 #include "kwset.h"
-#include "regex.h"
+#include "gnuregex.h"
 
 #define NCHAR (UCHAR_MAX + 1)