diff --git a/src/Vluzrmos/SlackApi/Contracts/SlackUser.php b/src/Vluzrmos/SlackApi/Contracts/SlackUser.php
index 0b6841d..c3f7cc2 100644
--- a/src/Vluzrmos/SlackApi/Contracts/SlackUser.php
+++ b/src/Vluzrmos/SlackApi/Contracts/SlackUser.php
@@ -10,4 +10,5 @@ public function lists();
     public function all();
     public function setActive();
     public function setPresence($presence);
+    public function lookupByEmail($email);
 }