diff --git a/jail2ban/__init__.py b/jail2ban/__init__.py
index a6fee1f..66aa24c 100644
--- a/jail2ban/__init__.py
+++ b/jail2ban/__init__.py
@@ -191,6 +191,8 @@ def create_app():
         Show a json parsable error if the value is illegal
         '''
         app.logger.fatal(error)
+        app.logger.fatal('stdout: %s', error.stderr)
+        app.logger.fatal('stderr: %s', error.stderr)
         return jsonify({'error': str(error)}), 500
 
     @app.errorhandler(FileNotFoundError)