diff --git a/ghc-blaze-builder.spec b/ghc-blaze-builder.spec
index 3f3a6fd..c665783 100644
--- a/ghc-blaze-builder.spec
+++ b/ghc-blaze-builder.spec
@@ -1,67 +1,85 @@
 %define ghc_ver %(ghc --version | sed "s|.*version ||")
-%define pkgname %(echo %name | sed "s|^ghc-||")
+%define pkg_name %(echo %name | sed "s|^ghc-||")
 
 Name:          ghc-blaze-builder
-Version:       0.3.3.4
-Release:       1mamba
 Epoch:         1
+Version:       0.4.2.3
+Release:       1mamba
 Summary:       GHC library: Efficient buffered output
 Group:         System/Libraries
 Vendor:        openmamba
 Distribution:  openmamba
 Packager:      Silvan Calarco <silvan.calarco@mambasoft.it>
-URL:           http://hackage.haskell.org/package/%{pkgname}
+URL:           http://hackage.haskell.org/package/%{pkg_name}
 Source:        http://hackage.haskell.org/package/blaze-builder-%{version}/blaze-builder-%{version}.tar.gz
 License:       BSD
 ## AUTOBUILDREQ-BEGIN
+BuildRequires: ghc-libs
+BuildRequires: glibc-devel
+BuildRequires: libgmp-devel
 ## AUTOBUILDREQ-END
 BuildRequires: ghc
-BuildRequires: haskell-platform
-BuildRequires: ghc-bytestring-builder
 Requires:      ghc = %{ghc_ver}
-BuildRoot:     %{_tmppath}/%{name}-%{version}-root
+Obsoletes:     ghc-bytestring-builder <= 0.10.8.2.0-1mamba
 
 %description
 This library provides an abstraction of buffered output of byte streams and several convenience functions to exploit it.
 For example, it allows to efficiently serialize Haskell values to lazy bytestrings with a large average chunk size.
 The large average chunk size allows to make good use of cache prefetching in later processing steps (e.g. compression) and reduces the sytem call overhead when writing the resulting lazy bytestring to a file or sending it over the network.
 
+%package devel
+Summary:        Haskell %{pkg_name} library development files
+Provides:       %{name}-static = %{?epoch:%epoch:}%{version}-%{release}
+Provides:       %{name}-static%{?_isa} = %{?epoch:%epoch:}%{version}-%{release}
+%if %{defined ghc_version}
+Requires:       ghc = %{ghc_version}
+%endif
+Requires:       %{name}%{?_isa} = %{?epoch:%epoch:}%{version}-%{release}
+
+%description devel
+This package provides the Haskell %{pkg_name} library development files.
+
+%if %{with haddock}
+%package doc
+Summary:        Haskell %{pkg_name} library documentation
+Requires:       ghc-filesystem
+
+%description doc
+This package provides the Haskell %{pkg_name} library documentation.
+%endif
+
 %prep
 %setup -q -n blaze-builder-%{version}
 
 %build
-runghc Setup.hs configure -v3 \
-   --prefix=%{_prefix} \
-   --libdir=%{_libdir} \
-   --libexecdir=%{_libexecdir} \
-   --docdir=%{_docdir}/%{name}-%{version}
-
-runghc Setup.hs build
-runghc Setup.hs haddock --executables --html-location=URL --hyperlink-source
+%ghc_lib_build
 
 %install
-[ "%{buildroot}" != / ] && rm -rf "%{buildroot}"
-runghc Setup.hs copy --destdir=%{buildroot}
-runghc Setup.hs register \
-   --gen-pkg-config="%{buildroot}%{_libdir}/ghc-%{ghc_ver}/%{pkgname}-%{version}/%{pkgname}-%{version}.conf"
+%ghc_lib_install
+
+rm -f %{buildroot}%{_ghclicensedir}/%{name}/LICENSE
 
 %clean
 [ "%{buildroot}" != / ] && rm -rf "%{buildroot}"
 
-%post
-ghc-pkg register %{_libdir}/ghc-%{ghc_ver}/%{pkgname}-%{version}/%{pkgname}-%{version}.conf &>/dev/null || :
-
-%preun
-ghc-pkg unregister %{_libdir}/ghc-%{ghc_ver}/%{pkgname}-%{version}/%{pkgname}-%{version}.conf &>/dev/null || :
-
-%files
+%files -f %{name}.files
 %defattr(-,root,root)
-%{_libdir}/ghc-%{ghc_ver}/%{pkgname}-%{version}
-%dir %{_docdir}/%{name}-%{version}
-%{_docdir}/%{name}-%{version}/LICENSE
-%{_docdir}/%{name}-%{version}/html
+%license LICENSE
+
+%files devel -f %{name}-devel.files
+%defattr(-,root,root)
+#%doc CHANGELOG.markdown README.markdown
+
+%if %{with haddock}
+%files doc -f %{name}-doc.files
+%defattr(-,root,root)
+%license LICENSE
+%endif
 
 %changelog
+* Sun Dec 03 2023 Silvan Calarco <silvan.calarco@mambasoft.it> 0.4.2.3-1mamba
+- update to 0.4.2.3
+
 * Sun Apr 12 2015 Davide Madrisan <davide.madrisan@gmail.com> 0.3.3.4-1mamba
 - update to 0.3.3.4