diff --git a/phpBB/phpbb/db/migration/data/v320/remove_outdated_media.php b/phpBB/phpbb/db/migration/data/v320/remove_outdated_media.php
new file mode 100644
index 0000000000..b2a0a79187
--- /dev/null
+++ b/phpBB/phpbb/db/migration/data/v320/remove_outdated_media.php
@@ -0,0 +1,83 @@
+<?php
+/**
+*
+* This file is part of the phpBB Forum Software package.
+*
+* @copyright (c) phpBB Limited <https://www.phpbb.com>
+* @license GNU General Public License, version 2 (GPL-2.0)
+*
+* For full copyright and license information, please see
+* the docs/CREDITS.txt file.
+*
+*/
+
+namespace phpbb\db\migration\data\v320;
+
+class remove_outdated_media extends \phpbb\db\migration\migration
+{
+	protected $cat_id = array(
+			ATTACHMENT_CATEGORY_WM,
+			ATTACHMENT_CATEGORY_RM,
+			ATTACHMENT_CATEGORY_QUICKTIME,
+		);
+
+	public function update_data()
+	{
+		return array(
+			array('custom', array(array($this, 'change_extension_group'))),
+		);
+	}
+
+	public function change_extension_group()
+	{
+		// select group ids of outdated media
+		$sql = 'SELECT group_id
+			FROM ' . EXTENSION_GROUPS_TABLE . '
+			WHERE ' . $this->db->sql_in_set('cat_id', $cat_id);
+		$result = $this->db->sql_query($sql);
+
+		$group_ids = array();
+		while ($group_id = (int) $this->db->sql_fetchfield('group_id'))
+		{
+			$group_ids[] = $group_id;
+		}
+		$this->db->sql_freeresult($result);
+
+		// nothing to do, admin has removed all the outdated media extension groups
+		if (empty($group_ids))
+		{
+			return true;
+		}
+
+		// get the group id of downloadable files
+		$sql = 'SELECT group_id
+			FROM ' . EXTENSION_GROUPS_TABLE . "
+			WHERE group_name = 'DOWNLOADABLE_FILES'";
+		$result = $this->db->sql_query($sql);
+		$download_id = (int) $this->db->sql_fetchfield('group_id');
+		$this->db->sql_freeresult($result);
+
+		if (empty($download_id))
+		{
+			$sql = 'UPDATE ' . EXTENSIONS_TABLE . '
+				SET group_id = 0
+				WHERE ' . $this->db->sql_in_set('group_id', $group_ids);
+		}
+		else
+		{
+			// move outdated media extensions to downloadable files
+			$sql = 'UPDATE ' . EXTENSIONS_TABLE . "
+				SET group_id = $download_id" . '
+				WHERE ' . $this->db->sql_in_set('group_id', $group_ids);
+		}
+
+		$result = $this->db->sql_query($sql);
+		$this->db->sql_freeresult($result);
+
+		// delete the now empty, outdated media extension groups
+		$sql = 'DELETE FROM ' . EXTENSION_GROUPS_TABLE . '
+			WHERE ' . $this->db->sql_in_set('group_id', $group_ids);
+		$result = $this->db->sql_query($sql);
+		$this->db->sql_freeresult($result);
+	}
+}