diff --git a/packages/wasm/wasm.2.0.1/opam b/packages/wasm/wasm.2.0.1/opam
index 118562fa596..407edbf9d78 100644
--- a/packages/wasm/wasm.2.0.1/opam
+++ b/packages/wasm/wasm.2.0.1/opam
@@ -14,6 +14,7 @@ depends: [
   "ocamlfind" {build}
   "ocamlbuild" {build}
 ]
+conflicts: ["ocaml-option-bytecode-only"] # uses ocamlopt unconconditionally
 synopsis:
   "Library to read and write WebAssembly (Wasm) files and manipulate their AST"
 url {