diff --git a/phpBB/install/install.php b/phpBB/install/install.php
index 8cefe04c92..7db904f7b8 100644
--- a/phpBB/install/install.php
+++ b/phpBB/install/install.php
@@ -225,6 +225,23 @@ function guess_lang()
 error_reporting  (E_ERROR | E_WARNING | E_PARSE); // This will NOT report uninitialized variables
 set_magic_quotes_runtime(0); // Disable magic_quotes_runtime
 
+// PHP5 with register_long_arrays off?
+if (!isset($HTTP_POST_VARS) && isset($_POST))
+{
+	$HTTP_POST_VARS = $_POST;
+	$HTTP_GET_VARS = $_GET;
+	$HTTP_SERVER_VARS = $_SERVER;
+	$HTTP_COOKIE_VARS = $_COOKIE;
+	$HTTP_ENV_VARS = $_ENV;
+	$HTTP_POST_FILES = $_FILES;
+
+	// _SESSION is the only superglobal which is conditionally set
+	if (isset($_SESSION))
+	{
+		$HTTP_SESSION_VARS = $_SESSION;
+	}
+}
+
 // Slash data if it isn't slashed
 if (!get_magic_quotes_gpc())
 {