diff --git a/opam b/opam
index b4cb96fa..b760ac53 100644
--- a/opam
+++ b/opam
@@ -12,7 +12,13 @@ install: [
 remove: [
     ["ocamlfind" "remove" "msat"]
 ]
-depends: ["ocamlfind" {build} "base-unix"]
+depends: [
+  "ocamlfind" {build}
+  "base-unix"
+]
+available: [
+  ocaml-version >= "4.02.1"
+]
 tags: [ "sat" "smt" ]
 homepage: "https://github.com/Gbury/mSAT"
 dev-repo: "https://github.com/Gbury/mSAT.git"