diff --git a/cobalt/build/gn.py b/cobalt/build/gn.py
index faa7291133b..43fffb9e162 100755
--- a/cobalt/build/gn.py
+++ b/cobalt/build/gn.py
@@ -84,7 +84,7 @@ def write_build_args(build_args_path, original_lines, dict_settings,
         f'The following args cannot be set in configs: {controlled_args}')
   gen_comment = '# Set by gn.py'
   with open(build_args_path, 'w', encoding='utf-8') as f:
-    if os.getenv('USE_RBE', default='0') == '0':
+    if os.getenv('IS_CI', default='0') == '1':
       f.write(f'cc_wrapper = "{CC_WRAPPER}" {gen_comment}\n')
     else:
       f.write(f'use_remoteexec = true {gen_comment}\n')
diff --git a/cobalt/docker/linux/Dockerfile b/cobalt/docker/linux/Dockerfile
index 9534beb6eaf..dfb50a8fcd2 100644
--- a/cobalt/docker/linux/Dockerfile
+++ b/cobalt/docker/linux/Dockerfile
@@ -30,7 +30,9 @@ RUN apt-get update && apt-get install -y \
 
 ADD files/sccache /usr/local/bin
 
+# TODO: b/379174067 - Move variables out of container.
 ENV SCCACHE_GCS_BUCKET=githubactions-chrome-sccache
 ENV SCCACHE_GCS_RW_MODE=READ_WRITE
 ENV SCCACHE_GCS_KEY_PATH=/root/key.json
 ENV SCCACHE_GCS_SERVICE_ACCOUNT=github-actions-bucket-access@cobalt-demo-330821.iam.gserviceaccount.com
+ENV IS_CI=1