diff --git a/mongoengine/queryset.py b/mongoengine/queryset.py
index 71e18932..73e333f0 100644
--- a/mongoengine/queryset.py
+++ b/mongoengine/queryset.py
@@ -597,7 +597,7 @@ class QuerySet(object):
 
         return mongo_update
 
-    def update(self, safe_update=True, **update):
+    def update(self, safe_update=True, upsert=False, **update):
         """Perform an atomic update on the fields matched by the query.
 
         :param safe: check if the operation succeeded before returning
@@ -611,14 +611,14 @@ class QuerySet(object):
         update = QuerySet._transform_update(self._document, **update)
         try:
             self._collection.update(self._query, update, safe=safe_update, 
-                                    multi=True)
+                                    upsert=upsert, multi=True)
         except pymongo.errors.OperationFailure, err:
             if unicode(err) == u'multi not coded yet':
                 message = u'update() method requires MongoDB 1.1.3+'
                 raise OperationError(message)
             raise OperationError(u'Update failed (%s)' % unicode(err))
 
-    def update_one(self, safe_update=True, **update):
+    def update_one(self, safe_update=True, upsert=False, **update):
         """Perform an atomic update on first field matched by the query.
 
         :param safe: check if the operation succeeded before returning
@@ -632,7 +632,7 @@ class QuerySet(object):
             # as the default may change to 'True'
             if pymongo.version >= '1.1.1':
                 self._collection.update(self._query, update, safe=safe_update, 
-                                        multi=False)
+                                        upsert=upsert, multi=False)
             else:
                 # Older versions of PyMongo don't support 'multi'
                 self._collection.update(self._query, update, safe=safe_update)