diff --git a/openbsc/src/gsm_04_08.c b/openbsc/src/gsm_04_08.c
index cd883a3..2373965 100644
--- a/openbsc/src/gsm_04_08.c
+++ b/openbsc/src/gsm_04_08.c
@@ -48,6 +48,7 @@
 #include <openbsc/rtp_proxy.h>
 #include <openbsc/talloc.h>
 #include <openbsc/transaction.h>
+#include <openbsc/ussd.h>
 
 #define GSM_MAX_FACILITY       128
 #define GSM_MAX_SSVERSION      128
@@ -3540,10 +3541,12 @@
 		break;
 	case GSM48_PDISC_MM_GPRS:
 	case GSM48_PDISC_SM_GPRS:
-	case GSM48_PDISC_NC_SS:  /* mobile-originated USSD */
 		fprintf(stderr, "Unimplemented GSM 04.08 discriminator 0x%02x\n",
 			pdisc);
 		break;
+	case GSM48_PDISC_NC_SS:
+		rc = handle_rcv_ussd(msg);
+		break;
 	default:
 		fprintf(stderr, "Unknown GSM 04.08 discriminator 0x%02x\n",
 			pdisc);