diff --git a/bin/cbuildbot.py b/bin/cbuildbot.py
index 6708c045b4..4e6f55243b 100755
--- a/bin/cbuildbot.py
+++ b/bin/cbuildbot.py
@@ -378,11 +378,20 @@ def _UprevPackages(buildroot, tracking_branch, revisionfile, board):
   _UprevAllPackages(buildroot, tracking_branch, board)
 
 
-def _UprevPush(buildroot, tracking_branch, board):
+def _UprevPush(buildroot, tracking_branch, board, overlays):
   """Pushes uprev changes to the main line."""
   cwd = os.path.join(buildroot, 'src', 'scripts')
+  public_overlay = '%s/src/third_party/chromiumos-overlay' % buildroot
+  private_overlay = '%s/src/private-overlays/chromeos-overlay' % buildroot
+  if overlays == 'private':
+    overlays = [private_overlay]
+  elif overlays == 'public':
+    overlays = [public_overlay]
+  else:
+    overlays = [public_overlay, private_overlay]
   RunCommand(['./cros_mark_as_stable', '--srcroot=..',
               '--board=%s' % board,
+              '--overlays="%s"' % " ".join(overlays),
               '--tracking_branch="%s"' % tracking_branch,
               '--push_options="--bypass-hooks -f"', 'push'],
              cwd=cwd)
@@ -531,7 +540,8 @@ def main():
         if buildconfig['master']:
           # Master bot needs to check if the other slaves completed.
           if cbuildbot_comm.HaveSlavesCompleted(config):
-            _UprevPush(buildroot, tracking_branch, buildconfig['board'])
+            _UprevPush(buildroot, tracking_branch, buildconfig['board'],
+                       buildconfig['overlays'])
           else:
             Die('CBUILDBOT - One of the slaves has failed!!!')
 
diff --git a/bin/cbuildbot_config.py b/bin/cbuildbot_config.py
index 2e68b0e43f..e0b0bfad0a 100644
--- a/bin/cbuildbot_config.py
+++ b/bin/cbuildbot_config.py
@@ -10,7 +10,7 @@ config_param's:
 board -- The board of the image to build.
 uprev -- Uprevs the local ebuilds to build new changes since last stable.
          build.  If master then also pushes these changes on success.
-master -- Only one allowed to be True.  This bot controls the uprev process.
+master -- This bot pushes changes to the overlays.
 important -- Master bot uses important bots to determine overall status.
              i.e. if master bot succeeds and other important slaves succeed
              then the master will uprev packages.  This should align
@@ -19,7 +19,9 @@ hostname -- Needed for 'important' slaves.  The hostname of the bot.  Should
             match hostname in slaves.cfg in buildbot checkout.
 unittests -- Runs unittests for packages.
 smoke_bvt -- Runs the test smoke suite in a qemu-based VM using KVM.
-
+overlays -- If this bot is a master bot, select what overlays to push changes
+            to. This can be 'public', 'private', or 'both'. There should only
+            be one bot pushing changes to each overlay.
 """
 
 
@@ -40,6 +42,32 @@ config['x86-generic-pre-flight-queue'] = {
   'hostname' : 'chromeosbuild2',
   'unittests' : True,
   'smoke_bvt' : True,
+  'overlays': 'public',
+}
+config['x86-mario-pre-flight-queue'] = {
+  'board' : 'x86-mario',
+  'uprev' : True,
+  'master' : True,
+  'important' : False,
+  'unittests' : True,
+  'smoke_bvt' : True,
+  'overlays': 'private',
+}
+config['x86_agz_bin'] = {
+  'board' : 'x86-agz',
+  'uprev' : True,
+  'master' : False,
+  'important' : False,
+  'unittests' : True,
+  'smoke_bvt' : True,
+}
+config['x86_dogfood_bin'] = {
+  'board' : 'x86-dogfood',
+  'uprev' : True,
+  'master' : False,
+  'important' : False,
+  'unittests' : True,
+  'smoke_bvt' : True,
 }
 config['x86_pineview_bin'] = {
   'board' : 'x86-pineview',
diff --git a/cros_mark_as_stable.py b/cros_mark_as_stable.py
index da017ad7af..fe8706c2b1 100755
--- a/cros_mark_as_stable.py
+++ b/cros_mark_as_stable.py
@@ -21,6 +21,9 @@ from cros_build_lib import Info, RunCommand, Warning, Die
 
 gflags.DEFINE_string('board', '',
                      'Board for which the package belongs.', short_name='b')
+gflags.DEFINE_string('overlays', '',
+                     'Space separated list of overlays to modify.',
+                     short_name='o')
 gflags.DEFINE_string('packages', '',
                      'Space separated list of packages to mark as stable.',
                      short_name='p')
@@ -479,11 +482,13 @@ def main(argv):
 
   package_list = gflags.FLAGS.packages.split()
   _CheckSaneArguments(package_list, command)
-
-  overlays = {
-    '%s/private-overlays/chromeos-overlay' % gflags.FLAGS.srcroot: [],
-    '%s/third_party/chromiumos-overlay' % gflags.FLAGS.srcroot: []
-  }
+  if gflags.FLAGS.overlays:
+    overlays = dict((path, []) for path in gflags.FLAGS.overlays.split())
+  else:
+    overlays = {
+      '%s/private-overlays/chromeos-overlay' % gflags.FLAGS.srcroot: [],
+      '%s/third_party/chromiumos-overlay' % gflags.FLAGS.srcroot: []
+    }
 
   if command == 'commit':
     _BuildEBuildDictionary(overlays, gflags.FLAGS.all, package_list)