diff --git a/infra/config/recipes.cfg b/infra/config/recipes.cfg
index da2e2fb..12c5524 100644
--- a/infra/config/recipes.cfg
+++ b/infra/config/recipes.cfg
@@ -16,12 +16,12 @@
   "deps": {
     "chromiumos_config": {
       "branch": "refs/heads/master",
-      "revision": "e37bd933ecade246eef70711a83f3c1d7739de70",
+      "revision": "c81b4a4267be0902ddd494a3493cb332189f0cb2",
       "url": "https://chromium.googlesource.com/chromiumos/config.git"
     },
     "recipe_engine": {
       "branch": "refs/heads/master",
-      "revision": "b2839ad3882c5f1412afbd31f72c45355e404932",
+      "revision": "79f951ca7bfd9a119dbe0cb27a51bf78493836bd",
       "url": "https://chromium.googlesource.com/infra/luci/recipes-py.git"
     }
   },
diff --git a/recipes/recipes.py b/recipes/recipes.py
index c6b37ae..c87581f 100755
--- a/recipes/recipes.py
+++ b/recipes/recipes.py
@@ -25,6 +25,7 @@
 
 # pylint: disable=wrong-import-position
 import argparse
+import errno
 import json
 import logging
 import os
@@ -195,6 +196,12 @@
     try:
       _git_check_call(['diff', '--quiet', revision], cwd=engine_path)
     except subprocess.CalledProcessError:
+      index_lock = os.path.join(engine_path, '.git', 'index.lock')
+      try:
+        os.remove(index_lock)
+      except OSError as exc:
+        if exc.errno != errno.EEXIST:
+          logging.warn('failed to remove %r, reset will fail: %s', index_lock, exc)
       _git_check_call(['reset', '-q', '--hard', revision], cwd=engine_path)
 
     # If the engine has refactored/moved modules we need to clean all .pyc files