diff --git a/openbsc/src/gprs/gprs_gmm.c b/openbsc/src/gprs/gprs_gmm.c
index da243a4..aa03891 100644
--- a/openbsc/src/gprs/gprs_gmm.c
+++ b/openbsc/src/gprs/gprs_gmm.c
@@ -116,6 +116,7 @@
 	{ MM_IDLE,		"MM IDLE" },
 	{ MM_READY,		"MM READY" },
 	{ MM_STANDBY,		"MM STANDBY" },
+	{ 0, NULL }
 };
 
 static int gsm48_gmm_authorize(struct sgsn_mm_ctx *ctx);