diff --git a/rwx/grub/__init__.py b/rwx/grub/__init__.py
index 21b2bf5..7c0cccc 100644
--- a/rwx/grub/__init__.py
+++ b/rwx/grub/__init__.py
@@ -25,8 +25,8 @@ def make_image(
     pubkey_path: str | None = None,
 ) -> None:
     """Make a binary bootable image."""
-    args = [
-        ("grub-mkimage",),
+    args: list[str | tuple[str, ...]] = [
+        "grub-mkimage",
         ("--compress", COMPRESSION),
         ("--format", image_format),
         ("--output", image_path),