diff --git a/src/Oauth2/Server.php b/src/Oauth2/Server.php
index a2492cf6..7d6b444d 100644
--- a/src/Oauth2/Server.php
+++ b/src/Oauth2/Server.php
@@ -303,7 +303,7 @@ maintenance of the server.'
      * @param  string $query_delimeter The query string delimiter (default: ?)
      * @return string                  The updated redirect URI
      */
-    public function redirectUri(string $redirectUri, $params = array(), 
+    public function redirectUri($redirectUri, $params = array(), 
      $queryDelimeter = '?')
     {