diff --git a/README.md b/README.md
index ad06e6f..a363dbf 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,10 @@ Portable Linux build and packaging for [ungoogled-chromium](https://github.com/u
 ## building
 execute `docker-build.sh` script in the root dir. This will
 * build a debian-based docker image with all needed llvm, nodejs and distro packages to build chromium
-* start the docker image, mounts the current dir and runs `build.sh` in it, which executes the actual build process on ungoogled-chromium (mainly: download chromium source tar, unpack and patch it, setup build env and execute ninja build on the result).
+* start the docker image, mounts the current dir and runs `build.sh` in it, which executes the actual build process on ungoogled-chromium (mainly: download chromium source tar, unpack 
+  and patch it, setup build env and execute ninja build on the result).
+* if you want to checkout chromium instead of downloading a tarball (e.g. because there's no tarball available yet), call `docker-build.sh -c`. 
+  Instead of tarball downloading this will call the `<ungoogled-chromium>/utils/clone.py` script for cloning the source tree of chromium and all needed submodules etc.
 
 >Note that the build takes several hours (about 8 hous on my computer) and consumes about 15G of disk space (you may delete the `build` dir __AFTER PACKAGING__, see [packaging](#packaging))
 
diff --git a/ungoogled-chromium b/ungoogled-chromium
index 0b5e403..a833234 160000
--- a/ungoogled-chromium
+++ b/ungoogled-chromium
@@ -1 +1 @@
-Subproject commit 0b5e4035314cb3da8956526db31806771ddf1238
+Subproject commit a833234d3919d1afb0fc59c7eea6f31fc8cf0453
diff --git a/use-oauth2-client-switches-as-default.patch b/use-oauth2-client-switches-as-default.patch
index 888b67b..118514d 100644
--- a/use-oauth2-client-switches-as-default.patch
+++ b/use-oauth2-client-switches-as-default.patch
@@ -1,18 +1,21 @@
-diff --git a/google_apis/google_api_keys-inc.cc b/google_apis/google_api_keys-inc.cc
-index 4d13e697a54d..61aac7b48662 100644
---- a/google_apis/google_api_keys-inc.cc
-+++ b/google_apis/google_api_keys-inc.cc
-@@ -193,11 +193,11 @@ class APIKeyCache {
-     std::string default_client_id = CalculateKeyValue(
-         GOOGLE_DEFAULT_CLIENT_ID,
-         STRINGIZE_NO_EXPANSION(GOOGLE_DEFAULT_CLIENT_ID), std::string(),
--        nullptr, std::string(), environment.get(), command_line, gaia_config);
-+        ::switches::kOAuth2ClientID, std::string(), environment.get(), command_line, gaia_config);
-     std::string default_client_secret = CalculateKeyValue(
-         GOOGLE_DEFAULT_CLIENT_SECRET,
-         STRINGIZE_NO_EXPANSION(GOOGLE_DEFAULT_CLIENT_SECRET), std::string(),
--        nullptr, std::string(), environment.get(), command_line, gaia_config);
-+        ::switches::kOAuth2ClientSecret, std::string(), environment.get(), command_line, gaia_config);
+diff --git a/google_apis/api_key_cache.cc b/google_apis/api_key_cache.cc
+index e8bc9bb79704..38e5d2bd005f 100644
+--- a/google_apis/api_key_cache.cc
++++ b/google_apis/api_key_cache.cc
+@@ -221,14 +221,14 @@ ApiKeyCache::ApiKeyCache(const DefaultApiKeys& default_api_keys) {
+ 
+   std::string default_client_id = CalculateKeyValue(
+       default_api_keys.google_default_client_id,
+-      STRINGIZE_NO_EXPANSION(GOOGLE_DEFAULT_CLIENT_ID), std::string(), nullptr,
++      STRINGIZE_NO_EXPANSION(GOOGLE_DEFAULT_CLIENT_ID), std::string(), ::switches::kOAuth2ClientID,
+       std::string(), environment.get(), command_line, gaia_config,
+       default_api_keys.allow_override_via_environment,
+       default_api_keys.allow_unset_values);
+   std::string default_client_secret = CalculateKeyValue(
+       default_api_keys.google_default_client_secret,
+       STRINGIZE_NO_EXPANSION(GOOGLE_DEFAULT_CLIENT_SECRET), std::string(),
+-      nullptr, std::string(), environment.get(), command_line, gaia_config,
++      ::switches::kOAuth2ClientSecret, std::string(), environment.get(), command_line, gaia_config,
+       default_api_keys.allow_override_via_environment,
+       default_api_keys.allow_unset_values);
  
-     // We currently only allow overriding the baked-in values for the
-     // default OAuth2 client ID and secret using a command-line