diff --git a/Dockerfile b/Dockerfile
index e8f717b7c..2000b49a3 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,7 +8,7 @@ RUN apt update &&\
 
 # Install Mermaid CLI globally
 ENV CHROME_BIN="/usr/bin/chromium" \
-    AM_I_IN_A_DOCKER_CONTAINER="true"
+    PUPPETEER_SKIP_CHROMIUM_DOWNLOAD="true"
 RUN npm install -g @mermaid-js/mermaid-cli &&\
     npm cache clean --force
 
diff --git a/metagpt/utils/mermaid.py b/metagpt/utils/mermaid.py
index 3850faae3..0fbc9f621 100644
--- a/metagpt/utils/mermaid.py
+++ b/metagpt/utils/mermaid.py
@@ -13,7 +13,7 @@ from metagpt.const import PROJECT_ROOT
 from metagpt.logs import logger
 from metagpt.utils.common import check_cmd_exists
 
-IS_DOCKER = os.environ.get('AM_I_IN_A_DOCKER_CONTAINER', 'false').lower()
+IS_DOCKER = os.environ.get('PUPPETEER_SKIP_CHROMIUM_DOWNLOAD', 'false').lower()
 
 
 def mermaid_to_file(mermaid_code, output_file_without_suffix, width=2048, height=2048) -> int: