diff --git a/src/Command/MailImportCommand.php b/src/Command/MailImportCommand.php
index 2d158ff..f7f6369 100644
--- a/src/Command/MailImportCommand.php
+++ b/src/Command/MailImportCommand.php
@@ -94,7 +94,7 @@ class MailImportCommand extends Command
             $attachmentsDirectory = $this->kernel->getProjectDir().'/private/attachments/'.$mailing->getId().'/'.$entity->getId();
 
             $filesystem = new Filesystem();
-            $filesystem->mkdir($attachmentsDirectory, 700);
+            $filesystem->mkdir($attachmentsDirectory, 0700);
 
             foreach ($attachments as $attachment) {
                 $filename = basename($attachment->save($attachmentsDirectory, Parser::ATTACHMENT_DUPLICATE_SUFFIX));