diff --git a/Dockerfile b/Dockerfile
index 62b0e10..c97ef81 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -12,4 +12,4 @@ RUN pip install --no-cache-dir .
 
 EXPOSE 8123
 
-CMD ["/bin/sh", "-c", "alembic upgrade head && exec uvicorn app.main:app --host 0.0.0.0 --port 8123"]
+CMD ["/bin/sh", "-c", "test -f \"$MASTER_KEY_PATH\" || { echo \"ERROR: master key not found at $MASTER_KEY_PATH -- run: docker compose run --rm app python scripts/generate_master_key.py\" >&2; exit 1; }; alembic upgrade head && exec uvicorn app.main:app --host 0.0.0.0 --port 8123"]