diff --git a/xdiff.php b/xdiff.php
index ef6eec8..1d59e56 100644
--- a/xdiff.php
+++ b/xdiff.php
@@ -38,7 +38,7 @@ class xdiff
   private $s2sWidth = 62;
 
   /** The constructor allow to choose the output.
-    * @param string $output The output mode [normal|unified]
+    * @param string $output The output mode [Normal|Unified|SideBySide]
     */
   public function __construct ($output = "normal")
   // {{{