diff --git a/phpBB/docs/CHANGELOG.html b/phpBB/docs/CHANGELOG.html
index 875dbf1400..1ba713b1b9 100644
--- a/phpBB/docs/CHANGELOG.html
+++ b/phpBB/docs/CHANGELOG.html
@@ -186,6 +186,7 @@
 		<li>[Fix] Do not try to create thumbnails for images we cannot open properly. (Bug #48695)</li>
 		<li>[Fix] Apply locale-independent basename() to attachment filenames. New function added: utf8_basename(). (Bug #43335 - Patch by ocean=Yohsuke)</li>
 		<li>[Fix] Adjust build_url() to not prepend $phpbb_root_path if path returned from redirect() is an URL. This fixes redirect issues with some installations and bridges. (Bug #47535)</li>
+		<li>[Fix] Fix general error while registration, through undefined variable $config in validate_referer (Bug #49035 - Patch by wjvriend)</li>
 		<li>[Change] Change the data format of the default file ACM to be more secure from tampering and have better performance.</li>
 		<li>[Change] Add index on log_time to the log table to prevent slowdown on boards with many log entries. (Bug #44665 - Patch by bantu)</li>
 		<li>[Change] Template engine now permits to a limited extent variable includes.</li>
diff --git a/phpBB/includes/session.php b/phpBB/includes/session.php
index a49716a8db..b4d817daf9 100644
--- a/phpBB/includes/session.php
+++ b/phpBB/includes/session.php
@@ -1364,6 +1364,8 @@ class session
 	*/
 	function validate_referer($check_script_path = false)
 	{
+		global $config;
+
 		// no referer - nothing to validate, user's fault for turning it off (we only check on POST; so meta can't be the reason)
 		if (empty($this->referer) || empty($this->host))
 		{
@@ -1373,7 +1375,7 @@ class session
 		$host = htmlspecialchars($this->host);
 		$ref = substr($this->referer, strpos($this->referer, '://') + 3);
 
-		if (!(stripos($ref, $host) === 0) && (!$config['force_server'] || !(stripos($ref, $config['server_name']) === 0)))
+		if (!(stripos($ref, $host) === 0) && (!$config['force_server_vars'] || !(stripos($ref, $config['server_name']) === 0)))
 		{
 			return false;
 		}