diff --git a/server.js b/server.js
index adf04488..4c3fd20b 100644
--- a/server.js
+++ b/server.js
@@ -93,7 +93,7 @@ app.put("/api/contacts/:id", function(req, res) {
   var updateDoc = req.body;
   delete updateDoc._id;
 
-  db.collection(CONTACTS_COLLECTION).updateOne({_id: new ObjectID(req.params.id)}, updateDoc, function(err, doc) {
+  db.collection(CONTACTS_COLLECTION).updateOne({_id: new ObjectID(req.params.id)}, {$set: updateDoc}, function(err, doc) {
     if (err) {
       handleError(res, err.message, "Failed to update contact");
     } else {