diff --git a/packages/alt-ergo/alt-ergo.2.4.2/opam b/packages/alt-ergo/alt-ergo.2.4.2/opam
index 3fde89088e4..fd7d41fe34d 100644
--- a/packages/alt-ergo/alt-ergo.2.4.2/opam
+++ b/packages/alt-ergo/alt-ergo.2.4.2/opam
@@ -33,6 +33,9 @@ build: [
   ["dune" "subst"] {dev}
   ["dune" "build" "-p" name "-j" jobs]
 ]
+conflicts: [
+  "ocaml-option-bytecode-only"
+]
 url {
   src: "https://github.com/OCamlPro/alt-ergo/archive/refs/tags/2.4.2.tar.gz"
   checksum: [