diff --git a/uuid_node/uuid_node.module b/uuid_node/uuid_node.module
index 0d8a925..b3a864f 100644
--- a/uuid_node/uuid_node.module
+++ b/uuid_node/uuid_node.module
@@ -7,8 +7,12 @@ module_load_include('inc', 'uuid');
  */
 function uuid_node_node_presave($node) {
   if (!$node->nid) {
-    $node->uuid = uuid_uuid();
-    $node->vuuid = uuid_uuid();
+    if (!isset($node->uuid) {
+      $node->uuid = uuid_uuid();
+    }
+    if (!isset($node->vuuid) {
+      $node->vuuid = uuid_uuid();
+    }
   }
   else {
     $old_node = node_load($node->nid);