diff --git a/opam/opam b/opam/opam
index 5066a6a..0936ca8 100644
--- a/opam/opam
+++ b/opam/opam
@@ -27,3 +27,5 @@ depends: [
   "ocamlbuild" {build}
   "ocamlfind" {build}
 ]
+
+available: [ ocaml-version >= "4.02.0" & ocaml-version <= "4.04.0" ]