diff --git a/lib/dao.js b/lib/dao.js
index fe406878..dad80cc1 100644
--- a/lib/dao.js
+++ b/lib/dao.js
@@ -361,7 +361,7 @@ DataAccessObject.updateOrCreate = DataAccessObject.upsert = function upsert(data
   var hookState = {};
 
   var id = getIdValue(this, data);
-  if (!id) {
+  if (id === undefined || id === null) {
     return this.create(data, options, cb);
   }