diff --git a/phpBB/includes/mcp/mcp_ban.php b/phpBB/includes/mcp/mcp_ban.php
index 4d2151fded..2f3405f915 100644
--- a/phpBB/includes/mcp/mcp_ban.php
+++ b/phpBB/includes/mcp/mcp_ban.php
@@ -28,7 +28,10 @@ class mcp_ban
 		global $db, $user, $auth, $template, $request, $phpbb_dispatcher;
 		global $phpbb_root_path, $phpEx;
 
-		include($phpbb_root_path . 'includes/functions_user.' . $phpEx);
+		if (!function_exists('user_ban'))
+		{
+			include($phpbb_root_path . 'includes/functions_user.' . $phpEx);
+		}
 
 		// Include the admin banning interface...
 		include($phpbb_root_path . 'includes/acp/acp_ban.' . $phpEx);
diff --git a/phpBB/includes/mcp/mcp_post.php b/phpBB/includes/mcp/mcp_post.php
index dd7aebdbd1..60ec3b8f5a 100644
--- a/phpBB/includes/mcp/mcp_post.php
+++ b/phpBB/includes/mcp/mcp_post.php
@@ -53,7 +53,10 @@ function mcp_post_details($id, $mode, $action)
 			if ($auth->acl_get('m_info', $post_info['forum_id']))
 			{
 				$ip = $request->variable('ip', '');
-				include($phpbb_root_path . 'includes/functions_user.' . $phpEx);
+				if (!function_exists('user_ipwhois'))
+				{
+					include($phpbb_root_path . 'includes/functions_user.' . $phpEx);
+				}
 
 				$template->assign_vars(array(
 					'RETURN_POST'	=> sprintf($user->lang['RETURN_POST'], '<a href="' . append_sid("{$phpbb_root_path}mcp.$phpEx", "i=$id&amp;mode=$mode&amp;p=$post_id") . '">', '</a>'),
diff --git a/phpBB/memberlist.php b/phpBB/memberlist.php
index 9fe91b96e6..75438283e6 100644
--- a/phpBB/memberlist.php
+++ b/phpBB/memberlist.php
@@ -105,7 +105,10 @@ switch ($mode)
 {
 	case 'team':
 		// Display a listing of board admins, moderators
-		include($phpbb_root_path . 'includes/functions_user.' . $phpEx);
+		if (!function_exists('user_get_id_name'))
+		{
+			include($phpbb_root_path . 'includes/functions_user.' . $phpEx);
+		}
 
 		$page_title = $user->lang['THE_TEAM'];
 		$template_html = 'memberlist_team.html';
diff --git a/phpBB/posting.php b/phpBB/posting.php
index 6d4c3cb395..0b6b9c5969 100644
--- a/phpBB/posting.php
+++ b/phpBB/posting.php
@@ -1073,7 +1073,10 @@ if ($submit || $preview || $refresh)
 	// Validate username
 	if (($post_data['username'] && !$user->data['is_registered']) || ($mode == 'edit' && $post_data['poster_id'] == ANONYMOUS && $post_data['username'] && $post_data['post_username'] && $post_data['post_username'] != $post_data['username']))
 	{
-		include($phpbb_root_path . 'includes/functions_user.' . $phpEx);
+		if (!function_exists('validate_username'))
+		{
+			include($phpbb_root_path . 'includes/functions_user.' . $phpEx);
+		}
 
 		$user->add_lang('ucp');
 
diff --git a/phpBB/viewonline.php b/phpBB/viewonline.php
index 238a184491..f1d4527c19 100644
--- a/phpBB/viewonline.php
+++ b/phpBB/viewonline.php
@@ -64,7 +64,10 @@ $order_by = $sort_key_sql[$sort_key] . ' ' . (($sort_dir == 'a') ? 'ASC' : 'DESC
 // Whois requested
 if ($mode == 'whois' && $auth->acl_get('a_') && $session_id)
 {
-	include($phpbb_root_path . 'includes/functions_user.' . $phpEx);
+	if (!function_exists('user_get_id_name'))
+	{
+		include($phpbb_root_path . 'includes/functions_user.' . $phpEx);
+	}
 
 	$sql = 'SELECT u.user_id, u.username, u.user_type, s.session_ip
 		FROM ' . USERS_TABLE . ' u, ' . SESSIONS_TABLE . " s