diff --git a/src/Composer/Util/RemoteFilesystem.php b/src/Composer/Util/RemoteFilesystem.php
index 676438c92..9ed465355 100644
--- a/src/Composer/Util/RemoteFilesystem.php
+++ b/src/Composer/Util/RemoteFilesystem.php
@@ -248,6 +248,7 @@ class RemoteFilesystem
         $maxFileSize = null;
         if (isset($options['max_file_size'])) {
             $maxFileSize = $options['max_file_size'];
+            unset($options['max_file_size']);
         }
 
         $ctx = StreamContextFactory::getContext($fileUrl, $options, array('notification' => array($this, 'callbackGet')));