diff --git a/phpBB/includes/functions.php b/phpBB/includes/functions.php
index 4d2a00f2db..0320230a7d 100644
--- a/phpBB/includes/functions.php
+++ b/phpBB/includes/functions.php
@@ -4553,7 +4553,7 @@ function page_header($page_title = '', $display_online_list = true, $item_id = 0
 		foreach ($_EXTRA_URL as $url_param)
 		{
 			$url_param = explode('=', $url_param, 2);
-			$s_hidden_fields[$url_param[0]] = $url_param[1];
+			$s_search_hidden_fields[$url_param[0]] = $url_param[1];
 		}
 	}
 
diff --git a/phpBB/viewforum.php b/phpBB/viewforum.php
index 588f60b589..6fec662b02 100644
--- a/phpBB/viewforum.php
+++ b/phpBB/viewforum.php
@@ -278,7 +278,7 @@ if (!empty($_EXTRA_URL))
 	foreach ($_EXTRA_URL as $url_param)
 	{
 		$url_param = explode('=', $url_param, 2);
-		$s_hidden_fields[$url_param[0]] = $url_param[1];
+		$s_search_hidden_fields[$url_param[0]] = $url_param[1];
 	}
 }
 
diff --git a/phpBB/viewtopic.php b/phpBB/viewtopic.php
index 01cd6a28a8..74420a25c7 100644
--- a/phpBB/viewtopic.php
+++ b/phpBB/viewtopic.php
@@ -607,7 +607,7 @@ if (!empty($_EXTRA_URL))
 	foreach ($_EXTRA_URL as $url_param)
 	{
 		$url_param = explode('=', $url_param, 2);
-		$s_hidden_fields[$url_param[0]] = $url_param[1];
+		$s_search_hidden_fields[$url_param[0]] = $url_param[1];
 	}
 }