diff --git a/gitea-to-ics.py b/gitea-to-ics.py
index a0e4df1..355249e 100644
--- a/gitea-to-ics.py
+++ b/gitea-to-ics.py
@@ -51,7 +51,10 @@ def process_combined(combined):
 def get_token(input_token):
     token = input_token.lstrip("Basic ")
     token = b64decode(token).decode('utf8', 'ignore')
-    _, token = token.split(":", 2)
+    try:
+        _, token = token.split(":", 2)
+    except ValueError:
+        raise cherrypy.HTTPError(401, 'Unauthorized')
     return token
 
 class Root: