diff --git a/README.md b/README.md
index f9d708b..82ce712 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,4 @@
 # ocaml-ppx_derivers
 
+Deriving plugin registry.
+
diff --git a/ocaml-ppx_derivers.spec b/ocaml-ppx_derivers.spec
new file mode 100644
index 0000000..05e1b7c
--- /dev/null
+++ b/ocaml-ppx_derivers.spec
@@ -0,0 +1,73 @@
+%define ocamlpck  ppx_derivers
+
+Name:          ocaml-ppx_derivers
+Version:       1.2.1
+Release:       1mamba
+Summary:       Deriving plugin registry
+Group:         System/Libraries/OCaml
+Vendor:        openmamba
+Distribution:  openmamba
+Packager:      Silvan Calarco <silvan.calarco@mambasoft.it>
+URL:           https://github.com/ocaml-ppx/ppx_derivers
+Source:        https://github.com/ocaml-ppx/ppx_derivers.git/%{version}/ppx_derivers-%{version}.tar.bz2
+License:       MMIT
+## AUTOBUILDREQ-BEGIN
+BuildRequires: glibc-devel
+BuildRequires: ocaml
+## AUTOBUILDREQ-END
+BuildRequires: ocaml
+BuildRequires: ocaml-camlp4-devel
+BuildRequires: ocaml-findlib
+BuildRequires: dune
+Requires:      ocaml-runtime
+
+%description
+Deriving plugin registry.
+
+%package devel
+Group:         Development/Libraries/OCaml
+Summary:       Development files for %{name}
+Requires:      %{name} = %{?epoch:%epoch:}%{version}-%{release}
+
+%description devel
+This package contains libraries and signature files for developing applications that use %{name}.
+
+%debug_package
+
+%prep
+%setup -q -n ppx_derivers-%{version}
+
+%build
+dune build
+
+%install
+[ "%{buildroot}" != / ] && rm -rf "%{buildroot}"
+DESTDIR=%{buildroot} dune install --prefix "/usr" --libdir "%{_lib}/ocaml"
+
+rm -rf %{buildroot}/usr/doc
+
+%clean
+[ "%{buildroot}" != / ] && rm -rf "%{buildroot}"
+
+%files
+%defattr(-,root,root)
+%dir %{_libdir}/ocaml/%{ocamlpck}
+%{_libdir}/ocaml/%{ocamlpck}/*
+%exclude %{_libdir}/ocaml/%{ocamlpck}/*.a
+%exclude %{_libdir}/ocaml/%{ocamlpck}/*.cmx
+%exclude %{_libdir}/ocaml/%{ocamlpck}/*.cmxa
+%exclude %{_libdir}/ocaml/%{ocamlpck}/*.mli
+#%{_libdir}/ocaml/stublibs/*.so*
+%doc LICENSE.md
+
+%files devel
+%defattr(-,root,root)
+%{_libdir}/ocaml/%{ocamlpck}/*.a
+%{_libdir}/ocaml/%{ocamlpck}/*.cmx
+%{_libdir}/ocaml/%{ocamlpck}/*.cmxa
+%{_libdir}/ocaml/%{ocamlpck}/*.mli
+%doc CHANGES.md README.md
+
+%changelog
+* Sun Jan 30 2022 Silvan Calarco <silvan.calarco@mambasoft.it> 1.2.1-1mamba
+- package created using the webbuild interface