diff --git a/bin/nsupdate/nsupdate.c b/bin/nsupdate/nsupdate.c
index a33693d512..9f7e57349d 100644
--- a/bin/nsupdate/nsupdate.c
+++ b/bin/nsupdate/nsupdate.c
@@ -2432,7 +2432,7 @@ do_next_command(char *cmdline) {
 static uint16_t
 get_next_command(void) {
 	uint16_t result = STATUS_QUIT;
-	char cmdlinebuf[MAXCMD];
+	char cmdlinebuf[MAXCMD] = { 0 };
 	char *cmdline = NULL, *ptr = NULL;
 
 	if (interactive) {