diff --git a/packages/spotlib/spotlib.4.0.0/opam b/packages/spotlib/spotlib.4.0.0/opam
index f71f8d4847c..38f93ec6bfb 100644
--- a/packages/spotlib/spotlib.4.0.0/opam
+++ b/packages/spotlib/spotlib.4.0.0/opam
@@ -24,5 +24,5 @@ depends: [
   "ppx_test" { >= "1.4.1" & < "1.6.0" }
 ]
 available: [
-  ocaml-version >= "4.04.0"
+  ocaml-version >= "4.04.0" & ocaml-version < "4.06.0"
 ]