diff --git a/api/auth/authproviders.py b/api/auth/authproviders.py
index 44b6a96e111d487b15817e1daeabcb0c58dac6a6..e96f258dcf61eb8438f4432af168de6927271bf6 100644
--- a/api/auth/authproviders.py
+++ b/api/auth/authproviders.py
@@ -296,7 +296,8 @@ class CASAuthProvider(AuthProvider):
         }
 
     def validate_user(self, token):
-        r = requests.get(self.config['verify_endpoint'], params={'ticket': token, 'service': self.config['service_url']})
+        service_url = config.get_item('site', 'redirect_url') + self.config['service_url_state']
+        r = requests.get(self.config['verify_endpoint'], params={'ticket': token, 'service': service_url})
         if not r.ok:
             raise APIAuthProviderException('User token not valid')