diff --git a/usr.bin/ctags/Makefile b/usr.bin/ctags/Makefile
index dd18da6e6fa9..1e25bf1666a4 100644
--- a/usr.bin/ctags/Makefile
+++ b/usr.bin/ctags/Makefile
@@ -2,8 +2,8 @@
 # $FreeBSD$
 
 PROG=	ctags
-CFLAGS+=-Wall
-CFLAGS+=-I${.CURDIR}
 SRCS=	C.c ctags.c fortran.c lisp.c print.c tree.c yacc.c
+CFLAGS+=-I${.CURDIR}
+WARNS?=	2
 
 .include <bsd.prog.mk>
diff --git a/usr.bin/ctags/ctags.c b/usr.bin/ctags/ctags.c
index 606731b7bf40..e99b1ed2c11b 100644
--- a/usr.bin/ctags/ctags.c
+++ b/usr.bin/ctags/ctags.c
@@ -88,7 +88,7 @@ main(argc, argv)
 	int	argc;
 	char	**argv;
 {
-	static char	*outfile = "tags";	/* output file */
+	static const char	*outfile = "tags";	/* output file */
 	int	aflag;				/* -a: append to tags */
 	int	uflag;				/* -u: update tags */
 	int	exit_val;			/* exit value */
@@ -199,7 +199,7 @@ void
 init()
 {
 	int		i;
-	unsigned char	*sp;
+	const unsigned char	*sp;
 
 	for (i = 0; i < 256; i++) {
 		_wht[i] = _etk[i] = _itk[i] = _btk[i] = NO;
diff --git a/usr.bin/ctags/ctags.h b/usr.bin/ctags/ctags.h
index b91aa411c3d8..1fc948b0e0a7 100644
--- a/usr.bin/ctags/ctags.h
+++ b/usr.bin/ctags/ctags.h
@@ -87,9 +87,9 @@ extern char	lbuf[LINE_MAX];
 extern char    *lbp;
 extern char	searchar;		/* ex search character */
 
-extern int	cicmp __P((char *));
+extern int	cicmp __P((const char *));
 extern void	getline __P((void));
-extern void	pfnote __P((char *, int));
+extern void	pfnote __P((const char *, int));
 extern int	skip_key __P((int));
 extern void	put_entries __P((NODE *));
 extern void	toss_yysec __P((void));
diff --git a/usr.bin/ctags/fortran.c b/usr.bin/ctags/fortran.c
index fbb3ceb14844..7e8417a7cd2a 100644
--- a/usr.bin/ctags/fortran.c
+++ b/usr.bin/ctags/fortran.c
@@ -140,7 +140,7 @@ PF_funcs()
  */
 int
 cicmp(cp)
-	char	*cp;
+	const char	*cp;
 {
 	int	len;
 	char	*bp;
diff --git a/usr.bin/ctags/tree.c b/usr.bin/ctags/tree.c
index 586930ed980b..9691fc9a8f22 100644
--- a/usr.bin/ctags/tree.c
+++ b/usr.bin/ctags/tree.c
@@ -56,7 +56,7 @@ static void	free_tree __P((NODE *));
  */
 void
 pfnote(name, ln)
-	char	*name;
+	const char	*name;
 	int	ln;
 {
 	NODE	*np;