diff --git a/include/backend/drm/drm.h b/include/backend/drm/drm.h
index c56850791..886c69688 100644
--- a/include/backend/drm/drm.h
+++ b/include/backend/drm/drm.h
@@ -32,7 +32,7 @@ struct wlr_drm_plane {
 	/* Buffer currently displayed on screen */
 	struct wlr_drm_fb current_fb;
 
-	uint32_t drm_format; // ARGB8888 or XRGB8888
+	uint32_t drm_format; // ARGB2101010, XRGB2101010, ARGB8888, or XRGB8888
 	struct wlr_drm_format_set formats;
 
 	// Only used by cursor