diff --git a/src/network/networkd-manager.c b/src/network/networkd-manager.c
index a10860b63b..8af17b1194 100644
--- a/src/network/networkd-manager.c
+++ b/src/network/networkd-manager.c
@@ -888,13 +888,17 @@ void manager_free(Manager *m) {
         m->rules_foreign = set_free(m->rules_foreign);
         set_free(m->rules_saved);
 
-        m->routes = set_free(m->routes);
-        m->routes_foreign = set_free(m->routes_foreign);
-
         sd_netlink_unref(m->rtnl);
         sd_netlink_unref(m->genl);
         sd_resolve_unref(m->resolve);
 
+        /* reject (e.g. unreachable) type routes are managed by Manager, but may be referenced by a
+         * link. E.g., DHCP6 with prefix delegation creates unreachable routes, and they are referenced
+         * by the upstream link. And the links may be referenced by netlink slots. Hence, two
+         * set_free() must be called after the above sd_netlink_unref(). */
+        m->routes = set_free(m->routes);
+        m->routes_foreign = set_free(m->routes_foreign);
+
         sd_event_source_unref(m->speed_meter_event_source);
         sd_event_unref(m->event);