diff --git a/i.php b/i.php
index 34afaba07..2d07a51e6 100644
--- a/i.php
+++ b/i.php
@@ -349,7 +349,6 @@ function send_derivative($expires)
   {
     header('Expires: '.gmdate('D, d M Y H:i:s', $expires).' GMT');
   }
-  header('Content-length: '.$fstat['size']);
   header('Connection: close');
 
   $ctype="application/octet-stream";
@@ -619,4 +618,4 @@ if ($logger->severity() >= Logger::DEBUG)
     'mem_usage' => function_exists('memory_get_peak_usage') ? round( memory_get_peak_usage()/(1024*1024), 1) : '',
     'timing' => $timing,
     ));
-}
\ No newline at end of file
+}