diff --git a/src/Promise.php b/src/Promise.php
index 33759e6f..f93ad58e 100644
--- a/src/Promise.php
+++ b/src/Promise.php
@@ -25,6 +25,9 @@ public function __construct(callable $resolver, callable $canceller = null)
         $this->call($cb);
     }
 
+    /**
+     * @return static
+     */
     public function then(callable $onFulfilled = null, callable $onRejected = null, callable $onProgress = null)
     {
         if (null !== $this->result) {