diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index da42f10..815c26b 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -12,6 +12,6 @@
       ]
     }
   },
-  "postCreateCommand": "pip install pytest && npm install -g @github/copilot && gh extension install github/gh-copilot",
+  "onCreateCommand": "pip install pytest && npm install -g @github/copilot && gh extension install github/gh-copilot",
   "postStartCommand": "echo '✅ Python, pytest, GitHub CLI, and Copilot CLI are ready. Run: cd samples/book-app-project && python book_app.py help'"
 }