diff --git a/src/gsm/gsup.c b/src/gsm/gsup.c
index af3c409..d6b4975 100644
--- a/src/gsm/gsup.c
+++ b/src/gsm/gsup.c
@@ -190,7 +190,7 @@
 	uint8_t *value;
 	size_t value_len;
 	static const struct osmo_gsup_pdp_info empty_pdp_info = {0};
-	static const struct osmo_auth_vector empty_auth_info = {0};
+	static const struct osmo_auth_vector empty_auth_info = {{0}};
 	static const struct osmo_gsup_message empty_gsup_message = {0};
 
 	*gsup_msg = empty_gsup_message;