diff --git a/lwt.opam b/lwt.opam
index 2c11eac3f..cb65673fe 100644
--- a/lwt.opam
+++ b/lwt.opam
@@ -54,3 +54,4 @@ build: [
     "@doc" {with-doc}
   ]
 ]
+available: os-family != "windows" | "ocaml-version" < "5.2"