diff --git a/openbsc/src/libmsc/auth.c b/openbsc/src/libmsc/auth.c
index 9191ae8..3b1fd73 100644
--- a/openbsc/src/libmsc/auth.c
+++ b/openbsc/src/libmsc/auth.c
@@ -39,6 +39,7 @@
 	AUTH_ACTION_STR(AUTH_DO_CIPH),
 	AUTH_ACTION_STR(AUTH_DO_AUTH),
 #undef AUTH_ACTION_STR
+	{ 0, NULL }
 };
 
 static int