diff --git a/boot.php b/boot.php
index 14458cd4f..350106c80 100755
--- a/boot.php
+++ b/boot.php
@@ -513,6 +513,7 @@ define ( 'ACTIVITY_MOOD',        NAMESPACE_ZOT . '/activity/mood' );
 define ( 'ACTIVITY_OBJ_COMMENT', NAMESPACE_ACTIVITY_SCHEMA . 'comment' );
 define ( 'ACTIVITY_OBJ_ACTIVITY',NAMESPACE_ACTIVITY_SCHEMA . 'activity' );
 define ( 'ACTIVITY_OBJ_NOTE',    NAMESPACE_ACTIVITY_SCHEMA . 'note' );
+define ( 'ACTIVITY_OBJ_ARTICLE', NAMESPACE_ACTIVITY_SCHEMA . 'article' );
 define ( 'ACTIVITY_OBJ_PERSON',  NAMESPACE_ACTIVITY_SCHEMA . 'person' );
 define ( 'ACTIVITY_OBJ_PHOTO',   NAMESPACE_ACTIVITY_SCHEMA . 'photo' );
 define ( 'ACTIVITY_OBJ_P_PHOTO', NAMESPACE_ACTIVITY_SCHEMA . 'profile-photo' );