diff --git a/proton b/proton
index e1a0dff4..da8282df 100755
--- a/proton
+++ b/proton
@@ -223,7 +223,7 @@ def copyfile_reflink(srcname, dstname):
                 while bytes_to_copy > 0:
                     bytes_to_copy -= copy_file_range(src.fileno(), dst.fileno(), bytes_to_copy)
         except OSError as e:
-            if e.errno != errno.EXDEV and e.errno != errno.ENOSYS:
+            if e.errno not in (errno.EXDEV, errno.ENOSYS, errno.EINVAL):
                 raise e
             if e.errno == errno.ENOSYS:
                 copyfile = shutil.copyfile