diff --git a/tests/test-subrepo-git.t b/tests/test-subrepo-git.t
--- a/tests/test-subrepo-git.t
+++ b/tests/test-subrepo-git.t
@@ -253,6 +253,7 @@ pulling new git branch should not create
 (issue3870)
   $ cd ../td/s
   $ git remote set-url origin $TESTTMP/tb/s
+  $ git branch --no-track oldtesting
   $ cd ..
   $ hg pull -q ../tb
   $ hg up