diff --git a/src/Composer/Util/RemoteFilesystem.php b/src/Composer/Util/RemoteFilesystem.php
index f2dfaf842..3ccb127ac 100644
--- a/src/Composer/Util/RemoteFilesystem.php
+++ b/src/Composer/Util/RemoteFilesystem.php
@@ -243,7 +243,7 @@ class RemoteFilesystem
             $options['http']['header'] .= "Authorization: Basic $authStr\r\n";
         }
 
-        $options = array_merge_recursive($options, $this->options);
+        $options = array_replace_recursive($options, $this->options);
 
         return $options;
     }