diff --git a/app/config.py b/app/config.py
index 52e0f53..60619bb 100644
--- a/app/config.py
+++ b/app/config.py
@@ -15,5 +15,5 @@ class Config:
     MAIL_DEFAULT_SENDER = os.environ.get('EMAIL_USER')
 
     MAX_SPOTS = 84
-    TUM_DOMAINS = ["@tum.de", "@mytum.de"]
+    TUM_DOMAINS = ("@tum.de", "@mytum.de")
     DISCORD_LINK = os.environ.get('DISCORD_LINK')