diff --git a/flaschengeist/app.py b/flaschengeist/app.py
index 7e4c8d2..ad44085 100644
--- a/flaschengeist/app.py
+++ b/flaschengeist/app.py
@@ -3,6 +3,7 @@ from flask import Flask, current_app
 from flask_cors import CORS
 from datetime import datetime, date
 from flask.json import JSONEncoder, jsonify
+from sqlalchemy.exc import OperationalError
 from werkzeug.exceptions import HTTPException
 
 from . import logger
@@ -93,6 +94,9 @@ def create_app():
         if isinstance(e, HTTPException):
             logger.debug(e.description, exc_info=True)
             return jsonify({"error": e.description}), e.code
+        if isinstance(e, OperationalError):
+            logger.error(e, exc_info=True)
+            return {"error": "Database unavailable"}, 504
         logger.error(str(e), exc_info=True)
         return jsonify({"error": "Internal server error occurred"}), 500
 
diff --git a/flaschengeist/controller/userController.py b/flaschengeist/controller/userController.py
index c912d9c..776dbce 100644
--- a/flaschengeist/controller/userController.py
+++ b/flaschengeist/controller/userController.py
@@ -1,4 +1,5 @@
 from flask import current_app
+from sqlalchemy.orm.exc import NoResultFound
 from werkzeug.exceptions import NotFound, BadRequest
 
 from flaschengeist.utils.hook import Hook
@@ -9,8 +10,9 @@ from flaschengeist import logger
 
 def login_user(username, password):
     logger.info("login user {{ {} }}".format(username))
-    user = User.query.filter(User.userid == username).one_or_none()
-    if user is None:
+    try:
+        user = User.query.filter(User.userid == username).one()
+    except NoResultFound:
         user = User(userid=username)
         db.session.add(user)
     if current_app.config["FG_AUTH_BACKEND"].login(user, password):