diff --git a/phpBB/includes/compatibility_globals.php b/phpBB/includes/compatibility_globals.php
index 464c553532..6a54097f56 100644
--- a/phpBB/includes/compatibility_globals.php
+++ b/phpBB/includes/compatibility_globals.php
@@ -24,6 +24,7 @@ if (!defined('IN_PHPBB'))
 define('ATTACHMENT_CATEGORY_WM', 2); // Windows Media Files - Streaming - @deprecated 3.2
 define('ATTACHMENT_CATEGORY_RM', 3); // Real Media Files - Streaming - @deprecated 3.2
 define('ATTACHMENT_CATEGORY_QUICKTIME', 6); // Quicktime/Mov files - @deprecated 3.2
+define('ATTACHMENT_CATEGORY_FLASH', 5); // Flash/SWF files - @deprecated 3.3
 
 /**
  * Sets compatibility globals in the global scope
diff --git a/phpBB/includes/constants.php b/phpBB/includes/constants.php
index dcab741366..d0319879dc 100644
--- a/phpBB/includes/constants.php
+++ b/phpBB/includes/constants.php
@@ -167,7 +167,6 @@ define('CONFIRM_REPORT', 4);
 define('ATTACHMENT_CATEGORY_NONE', 0);
 define('ATTACHMENT_CATEGORY_IMAGE', 1); // Inline Images
 define('ATTACHMENT_CATEGORY_THUMB', 4); // Not used within the database, only while displaying posts
-define('ATTACHMENT_CATEGORY_FLASH', 5); // Flash/SWF files
 
 // BBCode UID length
 define('BBCODE_UID_LEN', 8);