diff --git a/openbsc/src/gprs/gprs_gmm.c b/openbsc/src/gprs/gprs_gmm.c
index 88be512..dc73693 100644
--- a/openbsc/src/gprs/gprs_gmm.c
+++ b/openbsc/src/gprs/gprs_gmm.c
@@ -1415,7 +1415,7 @@
 	struct gprs_ra_id old_ra_id;
 	struct tlv_parsed tp;
 	uint8_t upd_type;
-	enum gsm48_gmm_cause reject_cause;
+	enum gsm48_gmm_cause reject_cause = GMM_CAUSE_PROTO_ERR_UNSPEC;
 	int rc;
 
 	/* TODO: In iu mode - handle follow-on request */