diff --git a/lib/framework.php b/lib/framework.php
index 350a1c268d..da96c8e1d4 100644
--- a/lib/framework.php
+++ b/lib/framework.php
@@ -33,6 +33,7 @@ define('AVATAR_MINI_SIZE', 24);
 
 define('NOTICES_PER_PAGE', 20);
 define('PROFILES_PER_PAGE', 20);
+define('MESSAGES_PER_PAGE', 20);
 
 define('FOREIGN_NOTICE_SEND', 1);
 define('FOREIGN_NOTICE_RECV', 2);