diff --git a/usr.bin/wall/ttymsg.c b/usr.bin/wall/ttymsg.c
index 3dccfbc81335..c65cfe8720d6 100644
--- a/usr.bin/wall/ttymsg.c
+++ b/usr.bin/wall/ttymsg.c
@@ -71,7 +71,7 @@ ttymsg(struct iovec *iov, int iovcnt, const char *line, int tmout)
 	if (iovcnt > sizeof(localiov) / sizeof(localiov[0]))
 		return ("too many iov's (change code in wall/ttymsg.c)");
 
-	strlcat(device, line, sizeof(device));
+	strlcpy(device + sizeof(_PATH_DEV) - 1, line, sizeof(device));
 	if (strchr(device + sizeof(_PATH_DEV) - 1, '/')) {
 		/* A slash is an attempt to break security... */
 		(void) snprintf(errbuf, sizeof(errbuf),