diff --git a/Dockerfile b/Dockerfile
index adbbb03..49efe66 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -66,6 +66,5 @@ ENV BUILD_DATE=${BUILD_DATE}
 
 # Run command
 EXPOSE 8000
-VOLUME ["/home/app/.local/share/spoolman"]
 ENTRYPOINT ["uvicorn", "spoolman.main:app"]
 CMD ["--host", "0.0.0.0", "--port", "8000"]
diff --git a/spoolman/env.py b/spoolman/env.py
index 60042f0..4cfc35f 100644
--- a/spoolman/env.py
+++ b/spoolman/env.py
@@ -326,3 +326,16 @@ def check_write_permissions() -> None:
                 gid,
             )
             sys.exit(1)
+
+
+def is_docker() -> bool:
+    """Check if we are running in a docker container."""
+    return Path("/.dockerenv").exists()
+
+
+def is_data_dir_mounted() -> bool:
+    """Check if the data directory is mounted as a shfs."""
+    # "mount" will give us a list of all mounted filesystems
+    mounts = subprocess.run("mount", check=True, stdout=subprocess.PIPE, text=True)  # noqa: S603, S607
+    data_dir = str(get_data_dir().resolve())
+    return any(data_dir in line for line in mounts.stdout.splitlines())
diff --git a/spoolman/main.py b/spoolman/main.py
index dc7fe12..0b4401e 100644
--- a/spoolman/main.py
+++ b/spoolman/main.py
@@ -95,6 +95,22 @@ async def startup() -> None:
 
     logger.info("Startup complete.")
 
+    if env.is_docker() and not env.is_data_dir_mounted():
+        logger.warning("!!!! WARNING !!!!")
+        logger.warning("!!!! WARNING !!!!")
+        logger.warning("The data directory is not mounted.")
+        logger.warning(
+            'Spoolman stores its database in the container directory "%s". '
+            "If this directory isn't mounted to the host OS, the database will be lost when the container is stopped.",
+            env.get_data_dir(),
+        )
+        logger.warning(
+            "Please carefully read the docker part of the README.md file, "
+            "and ensure your docker-compose file matches the example.",
+        )
+        logger.warning("!!!! WARNING !!!!")
+        logger.warning("!!!! WARNING !!!!")
+
 
 if __name__ == "__main__":
     uvicorn.run(app, host="0.0.0.0", port=8000)