diff --git a/src/visualCaptcha/Captcha.php b/src/visualCaptcha/Captcha.php
index <HASH>..<HASH> 100644
--- a/src/visualCaptcha/Captcha.php
+++ b/src/visualCaptcha/Captcha.php
@@ -277,7 +277,7 @@ class Captcha {
     }
 
     // Stream file from path
-    private function utilStreamFile( $headers, $filePath ) {
+    private function utilStreamFile( &$headers, $filePath ) {
         if ( !file_exists( $filePath ) ) {
             return false;
         }
[FIX] Adding the pointer on the functions definition:
utilStreamFile
streamAudio
streamImage