diff --git a/lib/libutil/pw_util.c b/lib/libutil/pw_util.c
index 207da8f0d5bf..fe99d7171b34 100644
--- a/lib/libutil/pw_util.c
+++ b/lib/libutil/pw_util.c
@@ -250,7 +250,7 @@ pw_error(name, err, eval)
 	extern int _use_yp;
 #endif /* YP */
 	if (err)
-		warn(name);
+		warn("%s", name);
 #ifdef YP
 	if (_use_yp)
 		warnx("NIS information unchanged");
diff --git a/usr.sbin/vipw/pw_util.c b/usr.sbin/vipw/pw_util.c
index 207da8f0d5bf..fe99d7171b34 100644
--- a/usr.sbin/vipw/pw_util.c
+++ b/usr.sbin/vipw/pw_util.c
@@ -250,7 +250,7 @@ pw_error(name, err, eval)
 	extern int _use_yp;
 #endif /* YP */
 	if (err)
-		warn(name);
+		warn("%s", name);
 #ifdef YP
 	if (_use_yp)
 		warnx("NIS information unchanged");
diff --git a/usr.sbin/vnconfig/vnconfig.c b/usr.sbin/vnconfig/vnconfig.c
index 779772038490..ad7e39ec60c6 100644
--- a/usr.sbin/vnconfig/vnconfig.c
+++ b/usr.sbin/vnconfig/vnconfig.c
@@ -317,7 +317,7 @@ config(vnp)
 	rdev = rawdevice(dev);
 	f = fopen(rdev, "rw");
 	if (f == NULL) {
-		warn(dev);
+		warn("%s", dev);
 		return(1);
 	}
 	vnio.vn_file = file;