diff --git a/php/src/file.php b/php/src/file.php
index 4c84f58..1045293 100644
--- a/php/src/file.php
+++ b/php/src/file.php
@@ -58,8 +58,8 @@ class file {
     return $file;
   }
 
-  static function writer($output, ?string $mode="w+b", ?callable $func=null): FileWriter {
-    $file = new FileWriter(self::fix_dash($output), $mode);
+  static function writer($output, ?callable $func=null): FileWriter {
+    $file = new FileWriter(self::fix_dash($output), "w+b");
     if ($func !== null) {
       try {
         $func($file);