diff --git a/include/class.file.php b/include/class.file.php
index 6908dd8eec6efb4e2a24a0618fd1945471859878..dcfc1e8d1d8b95d91079318adce5630dc77ef5cf 100644
--- a/include/class.file.php
+++ b/include/class.file.php
@@ -96,6 +96,7 @@ class AttachmentFile {
     }
 
     function sendData() {
+        @ini_set('zlib.output_compression', 'Off');
         $file = $this->open();
         while ($chunk = $file->read())
             echo $chunk;