diff --git a/_base.py b/_base.py
index c3f1690..c09c84e 100644
--- a/_base.py
+++ b/_base.py
@@ -118,6 +118,7 @@ class BaseUpdater(object):
                                     os.path.expanduser(
                                         os.path.join(self.grub_iso_dir,
                                                      self.dest_file)))))
+        os.chmod(self.grub_cfg, 0o0755)
         cmd = subprocess.run(['grub-mkconfig',
                               '-o', '{0}/grub/grub.cfg'.format(self.boot_dir)],
                              stdout = subprocess.PIPE,