diff --git a/src/api/api.c b/src/api/api.c
index c52f95a93..db8d725e9 100644
--- a/src/api/api.c
+++ b/src/api/api.c
@@ -1039,7 +1039,7 @@ z_owned_keyexpr_t z_publisher_keyexpr(z_publisher_t publisher) {
 }
 z_owned_keyexpr_t z_subscriber_keyexpr(z_subscriber_t sub) {
     z_owned_keyexpr_t ret = z_keyexpr_null();
-    __auto_type lookup = sub._val->_entity_id;
+    uint32_t lookup = sub._val->_entity_id;
     if (sub._val != NULL) {
         _z_subscription_sptr_list_t *tail = sub._val->_zn->_local_subscriptions;
         while (tail != NULL && !z_keyexpr_check(&ret)) {