gistfile1.txt

diff --git a/firestore/google/cloud/firestore_v1beta1/watch.py b/firestore/google/cloud/firestore_v1beta1/watch.py
index bc2b237bc1..a11313d6c3 100644
--- a/firestore/google/cloud/firestore_v1beta1/watch.py
+++ b/firestore/google/cloud/firestore_v1beta1/watch.py
@@ -619,10 +619,10 @@ class Watch(object):
             assert name in updated_map, 'Document to delete does not exist'
             old_document = updated_map.get(name)
             # XXX probably should not expose IndexError when doc doesnt exist
-            existing = updated_tree.find(old_document)
+            existing = updated_tree.find(name)
             old_index = existing.index
             # TODO: was existing.remove returning tree (presumably immuatable?)
-            updated_tree = updated_tree.remove(old_document)
+            updated_tree = updated_tree.remove(name)
             del updated_map[name]
             return (DocumentChange(ChangeType.REMOVED,
                                    old_document,