diff --git a/dune-project b/dune-project
index 80710ef..83de573 100644
--- a/dune-project
+++ b/dune-project
@@ -25,7 +25,7 @@
   "This repo contains:\n\n  1. a xenstore client library, a merge of the Mirage and XCP ones\n\n  2. a xenstore server library\n\n  3. a xenstore server instance which runs under Unix with libxc\n\n  4. a xenstore server instance which runs on mirage.\n\n\n  The client and the server libraries have sets of unit-tests.\n")
  (depends
   (ocaml
-   (>= 4.08.0))
+   (>= 4.13.0))
   (ounit2
    (>= 2.2.2))
   (lwt
diff --git a/xenstore.opam b/xenstore.opam
index bd558ac..d0558d3 100644
--- a/xenstore.opam
+++ b/xenstore.opam
@@ -28,7 +28,7 @@ homepage: "https://github.com/mirage/ocaml-xenstore"
 bug-reports: "https://github.com/mirage/ocaml-xenstore/issues"
 depends: [
   "dune" {>= "2.0"}
-  "ocaml" {>= "4.08.0"}
+  "ocaml" {>= "4.13.0"}
   "ounit2" {>= "2.2.2"}
   "lwt" {>= "4.5.0"}
 ]