diff --git a/openbsc/src/libmsc/ussd.c b/openbsc/src/libmsc/ussd.c
index 76ee101..b413c83 100644
--- a/openbsc/src/libmsc/ussd.c
+++ b/openbsc/src/libmsc/ussd.c
@@ -51,7 +51,7 @@
 	memset(&req, 0, sizeof(req));
 	gh = msgb_l3(msg);
 	rc = gsm0480_decode_ussd_request(gh, msgb_l3len(msg), &req);
-	if (req.text[0] == 0xFF)  /* Release-Complete */
+	if (req.text[0] == '\0')  /* Release-Complete */
 		return 0;
 
 	if (!strcmp(USSD_TEXT_OWN_NUMBER, (const char *)req.text)) {