diff --git a/phpBB/phpbb/content_visibility.php b/phpBB/phpbb/content_visibility.php
index de0e389dd1..c8516d6c85 100644
--- a/phpBB/phpbb/content_visibility.php
+++ b/phpBB/phpbb/content_visibility.php
@@ -244,6 +244,35 @@ class content_visibility
 
 		$approve_forums = array_diff(array_keys($this->auth->acl_getf('m_approve', true)), $exclude_forum_ids);
 
+		$visibility_sql_overwrite = null;
+
+		/**
+		* Allow changing the result of calling get_global_visibility_sql
+		*
+		* @event core.phpbb_content_visibility_get_global_visibility_before
+		* @var	array		where_sqls							The action the user tried to execute
+		* @var	string		mode								Either "topic" or "post" depending on the query this is being used in
+		* @var	array		forum_ids							Array of forum ids which the posts/topics are limited to
+		* @var	string		table_alias							Table alias to prefix in SQL queries
+		* @var	array		approve_forums						Array of forums where the user has m_approve permissions
+		* @var	string		visibility_sql_overwrite	Forces the function to return an implosion of where_sqls (joined by "OR")
+		* @since 3.1.3-RC1
+		*/
+		$vars = array(
+			'where_sqls',
+			'mode',
+			'forum_ids',
+			'table_alias',
+			'approve_forums',
+			'visibility_sql_overwrite',
+		);
+		extract($this->phpbb_dispatcher->trigger_event('core.phpbb_content_visibility_get_global_visibility_before', compact($vars)));
+
+		if ($visibility_sql_overwrite)
+		{
+			return $visibility_sql_overwrite;
+		}
+
 		if (sizeof($exclude_forum_ids))
 		{
 			$where_sqls[] = '(' . $this->db->sql_in_set($table_alias . 'forum_id', $exclude_forum_ids, true) . '