diff --git a/render/drm_format_set.c b/render/drm_format_set.c
index 3adef0b2..629327c0 100644
--- a/render/drm_format_set.c
+++ b/render/drm_format_set.c
@@ -162,6 +162,8 @@ bool wlr_drm_format_set_copy(struct wlr_drm_format_set *dst, const struct wlr_dr
 		out.len++;
 	}
 
+	*dst = out;
+
 	return true;
 }