diff --git a/cobalt/tools/on_device_tests_gateway_client.py b/cobalt/tools/on_device_tests_gateway_client.py
index 2afbba745b8..f977a7cff6c 100644
--- a/cobalt/tools/on_device_tests_gateway_client.py
+++ b/cobalt/tools/on_device_tests_gateway_client.py
@@ -297,8 +297,8 @@ def main() -> int:
   trigger_parser.add_argument(
       '--start_timeout_sec',
       type=str,
-      default='180',
-      help='Timeout in seconds for the test to start (default: 180 seconds).',
+      default='900',
+      help='Timeout in seconds for the test to start (default: 900 seconds).',
   )
 
   # Watch command