diff --git a/adsence/adsence.php b/adsence/adsence.php
index 1340fc9..9b2d956 100644
--- a/adsence/adsence.php
+++ b/adsence/adsence.php
@@ -13,7 +13,7 @@ function upgrade_info_load(){
 	Hook::register('conversation_start', 'addon/adsence/adsence.php', 'adsence');
 }
 function upgrade_info_unload(){
-	Hook::register('conversation_start', 'addon/adsence/adsence.php', 'adsence');
+	Hook::unregister('conversation_start', 'addon/adsence/adsence.php', 'adsence');
 }
 
 function adsence(&$b){