diff --git a/src/parse-nm.c b/src/parse-nm.c

index 9b09e34..6e042bf 100644

--- a/src/parse-nm.c

+++ b/src/parse-nm.c

@@ -136,7 +136,7 @@ static void

 handle_bridge_uint(GKeyFile* kf, const gchar* key, NetplanNetDefinition* nd, char** dataptr) {

     if (g_key_file_get_uint64(kf, "bridge", key, NULL)) {

         nd->custom_bridging = TRUE;

-        *dataptr = g_strdup_printf("%lu", g_key_file_get_uint64(kf, "bridge", key, NULL));

+        *dataptr = g_strdup_printf("%" G_GUINT64_FORMAT, g_key_file_get_uint64(kf, "bridge", key, NULL));

         _kf_clear_key(kf, "bridge", key);

     }

 }