     return originalUpdate.call @, msg unless collection
 
     mongoId = MongoID.idParse msg.id
-    doc = collection.findOne mongoId
+    doc = collection._collection.findOne mongoId
 
     # If a document is being added, but already exists, just change it.
     if msg.msg is 'added' and doc

originalDefineMutationMethods = Mongo.Collection::_defineMutationMethods
Mongo.Collection::_defineMutationMethods = ->
  if @_connection and @_connection.registerStore
    allCollections[@_name] = @_collection

  originalDefineMutationMethods.call @

Connection::registerStore = (name, wrappedStore) ->
  originalUpdate = wrappedStore.update
  wrappedStore.update = (msg) ->
    # TODO: Pending this pull request: https://github.com/meteor/meteor/pull/5845
    if wrappedStore._getCollection
      collection = wrappedStore._getCollection()
    else
      collection = allCollections[name]

    # We might still not have a collection for packages defining collections before
    # this package is loaded. But this is OK because those are packages which do not
