diff --git a/src/gprs/sgsn_auth.c b/src/gprs/sgsn_auth.c
index 6fb32b7..694bece 100644
--- a/src/gprs/sgsn_auth.c
+++ b/src/gprs/sgsn_auth.c
@@ -114,7 +114,7 @@
 			return mmctx->auth_state;
 
 		if (sgsn->cfg.require_authentication &&
-		    (!mmctx->is_authenticated ||
+		    (!sgsn_mm_ctx_is_authenticated(mmctx) ||
 		     mmctx->subscr->sgsn_data->auth_triplets_updated))
 			return SGSN_AUTH_AUTHENTICATE;
 
@@ -175,7 +175,7 @@
 
 	OSMO_ASSERT(mmctx->subscr != NULL);
 
-	if (sgsn->cfg.require_authentication && !mmctx->is_authenticated) {
+	if (sgsn->cfg.require_authentication && !sgsn_mm_ctx_is_authenticated(mmctx)) {
 		/* Find next tuple */
 		at = sgsn_auth_get_tuple(mmctx, mmctx->auth_triplet.key_seq);