diff --git a/src/Illuminate/Support/Collection.php b/src/Illuminate/Support/Collection.php
index d5e61c1..390d068 100644
--- a/src/Illuminate/Support/Collection.php
+++ b/src/Illuminate/Support/Collection.php
@@ -557,7 +557,7 @@ public function combine($values)
      * Union the collection with the given items.
      *
      * @param  mixed  $items
-     * @return void
+     * @return static
      */
     public function union($items)
     {