diff --git a/testing/mochitest/moz.build b/testing/mochitest/moz.build
index fe356ff130b..58029027066 100644
--- a/testing/mochitest/moz.build
+++ b/testing/mochitest/moz.build
@@ -5,6 +5,7 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 DIRS += [
+    'manifests',
     'tests',
     'ssltunnel',
 ]