diff --git a/docker/.env b/docker/.env
index ef5f0d886f..df2512f4c5 100644
--- a/docker/.env
+++ b/docker/.env
@@ -252,7 +252,7 @@ REGISTER_ENABLED=1
 #   - Node.js base image: includes axios
 #   - Python base image: includes requests, numpy, and pandas
 # Specify custom executor images below if you're using non-default environments.
-# SANDBOX_HOST=sandbox-executor-manager
+# SANDBOX_HOST=${SANDBOX_HOST:-sandbox-executor-manager}
 # SANDBOX_EXECUTOR_MANAGER_IMAGE=infiniflow/sandbox-executor-manager:latest
 # SANDBOX_EXECUTOR_MANAGER_POOL_SIZE=3
 # SANDBOX_BASE_PYTHON_IMAGE=infiniflow/sandbox-base-python:latest