diff --git a/runbot/runbot.py b/runbot/runbot.py
index 88b48756..6cb638a6 100644
--- a/runbot/runbot.py
+++ b/runbot/runbot.py
@@ -241,7 +241,7 @@ class runbot_repo(osv.osv):
         for repo in self.browse(cr, uid, ids, context=context):
             _logger.debug('checkout %s %s %s', repo.name, treeish, dest)
             p1 = subprocess.Popen(['git', '--git-dir=%s' % repo.path, 'archive', treeish], stdout=subprocess.PIPE)
-            p2 = subprocess.Popen(['tar', '-xC', dest], stdin=p1.stdout, stdout=subprocess.PIPE)
+            p2 = subprocess.Popen(['tar', '-xmC', dest], stdin=p1.stdout, stdout=subprocess.PIPE)
             p1.stdout.close()  # Allow p1 to receive a SIGPIPE if p2 exits.
             p2.communicate()[0]