diff --git a/utility/update.php b/utility/update.php
index 326fbded2aa6d6f87da3e26775b8a08f1de37a21..7e3161480139454301794a1e3a0bcd5d88220b4f 100644
--- a/utility/update.php
+++ b/utility/update.php
@@ -2204,6 +2204,10 @@ function buildarray($array, $level = 0, $pre = '$_config') {
 	}
 
 	foreach ($array as $key => $val) {
+		if(!preg_match("/^[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*$/", $key)) {
+			continue;
+		}
+
 		if($level == 0) {
 			$newline = str_pad('  CONFIG '.strtoupper($key).'  ', 70, '-', STR_PAD_BOTH);
 			$return .= "\r\n// $newline //\r\n";