diff --git a/src/Subfission/Cas/CasManager.php b/src/Subfission/Cas/CasManager.php
index 0b676e7..1526e85 100644
--- a/src/Subfission/Cas/CasManager.php
+++ b/src/Subfission/Cas/CasManager.php
@@ -119,7 +119,7 @@ public function getCurrentUser()
         return $this->user();
     }
 
-    public function logout($params)
+    public function logout($params = "")
     {
         if (phpCAS::isSessionAuthenticated()) {
             phpCAS::logout($params);