diff --git a/ocaml-labltk.spec b/ocaml-labltk.spec
index b31e756..2225577 100644
--- a/ocaml-labltk.spec
+++ b/ocaml-labltk.spec
@@ -10,7 +10,8 @@ Summary:       Tcl/Tk interface for OCaml
 License:       LGPL-2.1-or-later WITH OCaml-LGPL-linking-exception
 
 URL:           https://garrigue.github.io/labltk/
-Source0:       https://github.com/garrigue/labltk/archive/%{version}/labltk-%{version}.tar.gz
+VCS:           https://github.com/garrigue/labltk
+Source0:       %{vcs}/archive/%{version}/labltk-%{version}.tar.gz
 
 # This adds debugging (-g) everywhere.
 Patch1:        labltk-8.06.11-enable-debugging.patch