diff --git a/auth/cas/auth.php b/auth/cas/auth.php
index 5188d3f5322..20872e04001 100644
--- a/auth/cas/auth.php
+++ b/auth/cas/auth.php
@@ -102,6 +102,12 @@ class auth_plugin_cas extends auth_plugin_base {
 		  return;
 		  }
 
+	  if ($_GET["loginguest"]== true) {
+			$frm->username="guest";
+			$frm->password="guest";
+			return;
+	  }
+		  
 // Connection to CAS server
 	 $this->connectCAS();