diff --git a/ocaml-cppo.spec b/ocaml-cppo.spec
index 7456456..dc2413e 100644
--- a/ocaml-cppo.spec
+++ b/ocaml-cppo.spec
@@ -27,6 +27,7 @@ Source:		http://mjambon.com/releases/cppo/cppo-%{version}.tar.gz
 BuildRequires:	ocaml
 BuildRequires:	ocaml-easy-format
 BuildRequires:	ocaml-findlib
+BuildRequires:  ocaml(ocaml.opt)
 BuildRoot:      %{_tmppath}/%{name}-%{version}-build
 # ocaml autodep start for pkg: ocaml-cppo
 # hardcoded rpm dependency for pre 12.1 to compensate for lack of ocaml() provides/requires