diff --git a/backend/tests/test_liveuamap_docker_contract.py b/backend/tests/test_liveuamap_docker_contract.py
new file mode 100644
index 0000000..91bfa41
--- /dev/null
+++ b/backend/tests/test_liveuamap_docker_contract.py
@@ -0,0 +1,16 @@
+"""Static contract for the Playwright runtime-user packaging fix in #516."""
+from __future__ import annotations
+
+from pathlib import Path
+
+
+def test_dockerfile_uses_shared_playwright_browser_path_and_runtime_user_check() -> None:
+    dockerfile = Path(__file__).resolve().parents[1] / "Dockerfile"
+    text = dockerfile.read_text(encoding="utf-8")
+
+    assert "ENV PLAYWRIGHT_BROWSERS_PATH=/ms-playwright" in text
+    assert "playwright install --with-deps chromium" in text
+    assert "USER backenduser" in text
+    assert "p.chromium.executable_path" in text
+    assert "assert os.path.isfile(path)" in text
+    assert "chromium_headless_shell-*" in text