diff --git a/dune-workspace b/dune-workspace
index c338c1da4c..2c3db7875b 100644
--- a/dune-workspace
+++ b/dune-workspace
@@ -2,5 +2,7 @@
 
 (repository (name pinned_opam_repository) (url git+https://github.com/ocaml/opam-repository#584630e7a7e27e3cf56158696a3fe94623a0cf4f))
 
+(repository (name pinned_overlay_repository) (url git+https://github.com/ocaml-dune/opam-overlays#2a9543286ff0e0656058fee5c0da7abc16b8717d))
+
 (lock_dir
-  (repositories pinned_opam_repository))
+  (repositories pinned_opam_repository pinned_overlay_repository))