diff --git a/sagemaker_shim/cli.py b/sagemaker_shim/cli.py
index 3bf4b89..e3081a4 100644
--- a/sagemaker_shim/cli.py
+++ b/sagemaker_shim/cli.py
@@ -1,9 +1,11 @@
 import asyncio
 import logging.config
+import os
 import sys
 from collections.abc import Callable, Coroutine
 from functools import wraps
 from json import JSONDecodeError
+from pathlib import Path
 from typing import Any, TypeVar
 
 import click
@@ -28,9 +30,19 @@ def wrapper(*args: Any, **kwargs: Any) -> T:
     return wrapper
 
 
+def _ensure_directories_are_writable() -> None:
+    for directory in os.environ.get(
+        "GRAND_CHALLENGE_COMPONENT_WRITABLE_DIRECTORIES", ""
+    ).split(":"):
+        path = Path(directory)
+        path.mkdir(exist_ok=True, parents=True)
+        path.chmod(mode=0o777)
+
+
 @click.group()
 def cli() -> None:
     logging.config.dictConfig(LOGGING_CONFIG)
+    _ensure_directories_are_writable()
 
 
 @cli.command(short_help="Start the model server")
diff --git a/tests/test_cli.py b/tests/test_cli.py
index efcabb3..01406d4 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -218,3 +218,30 @@ def test_logging_stderr_setup(minio, monkeypatch):
         '{"log": "hello", "level": "WARNING", '
         f'"source": "stderr", "internal": false, "task": "{pk}"}}'
     ) in result.output
+
+
+def test_ensure_directories_are_writable(tmp_path, monkeypatch):
+    data = tmp_path / "opt" / "ml" / "output" / "data"
+    data.mkdir(mode=0o755, parents=True)
+
+    model = tmp_path / "opt" / "ml" / "model"
+    model.mkdir(mode=0o755, parents=True)
+
+    # Do not create the checkpoints dir in the test
+    checkpoints = tmp_path / "opt" / "ml" / "checkpoints"
+
+    tmp = tmp_path / "tmp"
+    tmp.mkdir(mode=0o755)
+
+    monkeypatch.setenv(
+        "GRAND_CHALLENGE_COMPONENT_WRITABLE_DIRECTORIES",
+        f"{data.absolute()}:{model.absolute()}:{checkpoints.absolute()}:{tmp.absolute()}",
+    )
+
+    runner = CliRunner()
+    runner.invoke(cli, ["invoke"])
+
+    assert data.stat().st_mode == 0o40777
+    assert model.stat().st_mode == 0o40777
+    assert checkpoints.stat().st_mode == 0o40777
+    assert tmp.stat().st_mode == 0o40777