1 files changed, 1 insertions, 1 deletions
diff --git a/synapse/config/cas.py b/synapse/config/cas.py
index 901f4123e1..9b58ecf3d8 100644
--- a/synapse/config/cas.py
+++ b/synapse/config/cas.py
@@ -37,7 +37,7 @@ class CasConfig(Config):
 
             # The public baseurl is required because it is used by the redirect
             # template.
-            public_baseurl = self.public_baseurl
+            public_baseurl = self.root.server.public_baseurl
             if not public_baseurl:
                 raise ConfigError("cas_config requires a public_baseurl to be set")