diff --git a/phpBB/common.php b/phpBB/common.php
index 5518fb6f0a..4fab61ca67 100644
--- a/phpBB/common.php
+++ b/phpBB/common.php
@@ -51,10 +51,10 @@ if (!defined('PHPBB_INSTALLED'))
 		$server_port = 443;
 	}
 
-	$script_name = (!empty($_SERVER['PHP_SELF'])) ? $_SERVER['PHP_SELF'] : getenv('PHP_SELF');
+	$script_name = (!empty($_SERVER['REQUEST_URI'])) ? $_SERVER['REQUEST_URI'] : getenv('REQUEST_URI');
 	if (!$script_name)
 	{
-		$script_name = (!empty($_SERVER['REQUEST_URI'])) ? $_SERVER['REQUEST_URI'] : getenv('REQUEST_URI');
+		$script_name = (!empty($_SERVER['PHP_SELF'])) ? $_SERVER['PHP_SELF'] : getenv('PHP_SELF');
 	}
 
 	// $phpbb_root_path accounts for redirects from e.g. /adm
diff --git a/phpBB/includes/functions_messenger.php b/phpBB/includes/functions_messenger.php
index 27865cbe54..fa47c50b49 100644
--- a/phpBB/includes/functions_messenger.php
+++ b/phpBB/includes/functions_messenger.php
@@ -427,7 +427,7 @@ class messenger
 			$user->session_begin();
 		}
 
-		$calling_page = html_entity_decode($request->server('PHP_SELF'), ENT_COMPAT);
+		$calling_page = html_entity_decode($request->server('REQUEST_URI'), ENT_COMPAT);
 
 		switch ($type)
 		{
diff --git a/phpBB/phpbb/install/module/obtain_data/task/obtain_server_data.php b/phpBB/phpbb/install/module/obtain_data/task/obtain_server_data.php
index 002bd9b331..7116ab49d4 100644
--- a/phpBB/phpbb/install/module/obtain_data/task/obtain_server_data.php
+++ b/phpBB/phpbb/install/module/obtain_data/task/obtain_server_data.php
@@ -65,11 +65,11 @@ class obtain_server_data extends \phpbb\install\task_base implements \phpbb\inst
 			$server_name = substr($server_name, 0, strpos($server_name, ':'));
 		}
 
-		$script_path = html_entity_decode($this->io_handler->get_server_variable('PHP_SELF'), ENT_COMPAT);
+		$script_path = html_entity_decode($this->io_handler->get_server_variable('REQUEST_URI'), ENT_COMPAT);
 
 		if (!$script_path)
 		{
-			$script_path = html_entity_decode($this->io_handler->get_server_variable('REQUEST_URI'), ENT_COMPAT);
+			$script_path = html_entity_decode($this->io_handler->get_server_variable('PHP_SELF'), ENT_COMPAT);
 		}
 
 		$script_path = str_replace(array('\\', '//'), '/', $script_path);