diff --git a/docs_src/security/tutorial004_an_py39.py b/docs_src/security/tutorial004_an_py39.py
index d3fd29e5a..7719c25cd 100644
--- a/docs_src/security/tutorial004_an_py39.py
+++ b/docs_src/security/tutorial004_an_py39.py
@@ -1,3 +1,4 @@
+import os
 from datetime import datetime, timedelta, timezone
 from typing import Annotated, Union
 
@@ -10,7 +11,7 @@ from pydantic import BaseModel
 
 # to get a string like this run:
 # openssl rand -hex 32
-SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
+SECRET_KEY = os.environ.get("SECRET_KEY", "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7")
 ALGORITHM = "HS256"
 ACCESS_TOKEN_EXPIRE_MINUTES = 30