--- a/browser/moz.build
+++ b/browser/moz.build
@@ -11,12 +11,10 @@ SPHINX_TREES['browser'] = 'docs'
 DIRS += [
     'base',
     'components',
-    'experiments',
     'fonts',
     'locales',
     'modules',
     'themes',
-    'extensions',
 ]
 
 DIRS += [
@@ -27,7 +25,6 @@ if CONFIG['MAKENSISU']:
     DIRS += ['installer/windows']
 
 TEST_DIRS += [
-    'tools/mozscreenshots',
 ]
 
 DIST_SUBDIR = 'browser'