diff --git a/src/app.py b/src/app.py
index 2c596f4..a451a35 100644
--- a/src/app.py
+++ b/src/app.py
@@ -37,11 +37,12 @@ if SENTRY_DSN:
 
 app = Flask(__name__)
 app.config['MQTT_BROKER_URL'] = MQTT_HOSTNAME
+MQTT_PORT = int(MQTT_PORT)
 app.config['MQTT_BROKER_PORT'] = MQTT_PORT
 app.config['MQTT_USERNAME'] = MQTT_USERNAME
 app.config['MQTT_PASSWORD'] = MQTT_PASSWORD
 app.config['MQTT_REFRESH_TIME'] = 1.0  # refresh time in seconds
-app.config['SQLALCHEMY_DATABASE_URI'] =\
+app.config['SQLALCHEMY_DATABASE_URI'] = \
     f"postgresql://{POSTGRES_USERNAME}:{POSTGRES_PASSWORD}@{POSTGRES_HOSTNAME}:5432/{POSTGRES_DB}"
 
 api = Api(app)