diff --git a/packages/mongo/mongo_common.js b/packages/mongo/mongo_common.js
index 9e1c95a768..c6d0953726 100644
--- a/packages/mongo/mongo_common.js
+++ b/packages/mongo/mongo_common.js
@@ -77,7 +77,7 @@ export const replaceMeteorAtomWithMongo = function (document) {
   if (document instanceof MongoDB.Binary) {
     return document;
   }
-  if (document instanceof Mongo.ObjectID) {
+  if (document instanceof MongoDB.ObjectId) {
     return new MongoDB.ObjectId(document.toHexString());
   }
   if (document instanceof MongoDB.Timestamp) {