diff --git a/run_flaschengeist b/run_flaschengeist
index 03d3222..1aca1be 100644
--- a/run_flaschengeist
+++ b/run_flaschengeist
@@ -5,7 +5,7 @@ import argparse
 import sys
 
 import pkg_resources
-from sqlalchemy import exc
+from os import environ
 
 from flaschengeist.app import create_app, install_all
 from flaschengeist.config import config
@@ -142,6 +142,7 @@ def run(arguments):
     with app.app_context():
         app.wsgi_app = PrefixMiddleware(app.wsgi_app, prefix=config["FLASCHENGEIST"].get("root", ""))
         if arguments.debug:
+            environ["FLASK_DEBUG"] = "1"
             app.run(arguments.host, arguments.port, debug=True)
         else:
             app.run(arguments.host, arguments.port, debug=False)