diff --git a/autotest b/autotest
index 1ab04e3083..823ea91c33 100755
--- a/autotest
+++ b/autotest
@@ -185,6 +185,7 @@ def build_autotest(options):
   environ['TEST_LIST'] = test_list
   environ['USE'] = use_flag
   emerge_cmd = ['emerge-%s' % options.board,
+                '-uDn',
                 'chromeos-base/autotest']
   if emerge_jobs:
     emerge_cmd.append(emerge_jobs)