diff --git a/apps/app_senddtmf.c b/apps/app_senddtmf.c
index 9863ce0121..5a64ab1b0e 100644
--- a/apps/app_senddtmf.c
+++ b/apps/app_senddtmf.c
@@ -92,7 +92,7 @@ static int manager_play_dtmf(struct mansession *s, const struct message *m)
 		astman_send_error(s, m, "Channel not specified");
 		return 0;
 	}
-	if (!digit) {
+	if (ast_strlen_zero(digit)) {
 		astman_send_error(s, m, "No digit specified");
 		ast_channel_unlock(chan);
 		return 0;