diff --git a/README.md b/README.md
index 75ba69f..a914ae4 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,5 @@
 # systemd-cron
 
+systemd units to provide cron daemon functionality by running scripts in cron directories.
+The crontabs are automaticaly translated using (/usr)/lib/systemd/system-generators/systemd-crontab-generator.
+
diff --git a/systemd-cron-1.5.17-cron-failure-disable-DynamicUser.patch b/systemd-cron-1.5.17-cron-failure-disable-DynamicUser.patch
new file mode 100644
index 0000000..c58f1d5
--- /dev/null
+++ b/systemd-cron-1.5.17-cron-failure-disable-DynamicUser.patch
@@ -0,0 +1,9 @@
+--- systemd-cron-1.5.17/src/units/cron-failure@.service.in.orig	2021-03-25 16:47:55.125066343 +0100
++++ systemd-cron-1.5.17/src/units/cron-failure@.service.in	2021-03-25 16:48:00.602163196 +0100
+@@ -8,5 +8,5 @@
+ [Service]
+ Type=oneshot
+ ExecStart=@libdir@/@package@/mail_on_failure %i
+-DynamicUser=yes
++#DynamicUser=yes
+ Group=systemd-journal
diff --git a/systemd-cron-crontab b/systemd-cron-crontab
new file mode 100644
index 0000000..aac4a53
--- /dev/null
+++ b/systemd-cron-crontab
@@ -0,0 +1,10 @@
+SHELL=/bin/bash
+PATH=/sbin:/bin:/usr/sbin:/usr/bin
+MAILTO=root
+HOME=/
+
+# run-parts
+01 * * * * root nice -n 19 run-parts /etc/cron.hourly
+02 4 * * * root nice -n 19 run-parts /etc/cron.daily
+22 4 * * 0 root nice -n 19 run-parts /etc/cron.weekly
+42 4 1 * * root nice -n 19 run-parts /etc/cron.monthly
diff --git a/systemd-cron-sysusers.conf b/systemd-cron-sysusers.conf
new file mode 100644
index 0000000..be3c0eb
--- /dev/null
+++ b/systemd-cron-sysusers.conf
@@ -0,0 +1,2 @@
+g   crontab -   -
+
diff --git a/systemd-cron.spec b/systemd-cron.spec
new file mode 100644
index 0000000..592a997
--- /dev/null
+++ b/systemd-cron.spec
@@ -0,0 +1,147 @@
+Name:          systemd-cron
+Version:       1.5.17
+Release:       2mamba
+Summary:       systemd units to provide cron daemon functionality by running scripts in cron directories
+Group:         System/Servers
+Vendor:        openmamba
+Distribution:  openmamba
+Packager:      Silvan Calarco <silvan.calarco@mambasoft.it>
+URL:           https://github.com/systemd-cron
+Source:        https://github.com/systemd-cron/systemd-cron.git/v%{version}/systemd-cron-%{version}.tar.bz2
+Source1:       systemd-cron-sysusers.conf
+Source2:       systemd-cron-crontab
+Patch0:        systemd-cron-1.5.17-cron-failure-disable-DynamicUser.patch
+License:       MIT
+## AUTOBUILDREQ-BEGIN
+BuildRequires: glibc-devel
+BuildRequires: ldconfig
+## AUTOBUILDREQ-END
+%systemd_requires
+Requires:      debianutils
+Requires:      postfix
+Provides:      vixie-cron
+Obsoletes:     vixie-cron <= 4.1-3mamba
+
+%description
+systemd units to provide cron daemon functionality by running scripts in cron directories.
+The crontabs are automaticaly translated using (/usr)/lib/systemd/system-generators/systemd-crontab-generator.
+
+%debug_package
+
+%prep
+%setup -q
+sed -i "s|/usr/bin/touch|/bin/touch|" src/units/cron-update.service.in
+%patch0 -p1
+
+%build
+./configure \
+   --prefix=%{_prefix} \
+   --unitdir=%{_unitdir} \
+   --generatordir=%{_systemdgeneratordir} \
+   --confdir=%{_sysconfdir} \
+   --enable-minutely --enable-quarterly --enable-semi_annually --enable-yearly \
+   --enable-persistent --enable-setgid --enable-randomized-delay
+
+%make
+
+%install
+[ "%{buildroot}" != / ] && rm -rf "%{buildroot}"
+%makeinstall
+
+install -d %{buildroot}%{_sysconfdir}/cron.{d,boot,minutely,hourly,daily,weekly,monthly,quarterly,semi-annually,yearly}
+install -d -m0775 %{buildroot}/var/spool/cron
+install -D -m0644 %{SOURCE1} %{buildroot}%{_sysusersdir}/systemd-cron.conf
+install -D -m0644 %{SOURCE2} %{buildroot}%{_sysconfdir}/crontab
+
+install -d -m0755 %{buildroot}%{_presetdir}
+echo "enable cron.target" > %{buildroot}%{_presetdir}/50-systemd-cron.preset
+
+%clean
+[ "%{buildroot}" != / ] && rm -rf "%{buildroot}"
+
+%pre
+%sysusers_create_package systemd-cron %{SOURCE1}
+:
+
+%post
+touch /run/crond.reboot
+touch /run/crond.bootdir
+%systemd_post cron.target
+:
+
+%preun
+%systemd_preun cron.target
+:
+
+%postun
+%systemd_postun cron.target
+:
+
+
+%files
+%defattr(-,root,root)
+%config(noreplace) %{_sysconfdir}/crontab
+%dir %{_sysconfdir}/cron.boot
+%dir %{_sysconfdir}/cron.d
+%dir %{_sysconfdir}/cron.minutely
+%dir %{_sysconfdir}/cron.hourly
+%dir %{_sysconfdir}/cron.daily
+%dir %{_sysconfdir}/cron.weekly
+%dir %{_sysconfdir}/cron.monthly
+%dir %{_sysconfdir}/cron.quarterly
+%dir %{_sysconfdir}/cron.semi-annually
+%dir %{_sysconfdir}/cron.yearly
+%{_bindir}/crontab
+%{_unitdir}/cron-boot.service
+%{_unitdir}/cron-boot.target
+%{_unitdir}/cron-boot.timer
+%{_unitdir}/cron-daily.service
+%{_unitdir}/cron-daily.target
+%{_unitdir}/cron-daily.timer
+%{_unitdir}/cron-failure@.service
+%{_unitdir}/cron-hourly.service
+%{_unitdir}/cron-hourly.target
+%{_unitdir}/cron-hourly.timer
+%{_unitdir}/cron-minutely.service
+%{_unitdir}/cron-minutely.target
+%{_unitdir}/cron-minutely.timer
+%{_unitdir}/cron-monthly.service
+%{_unitdir}/cron-monthly.target
+%{_unitdir}/cron-monthly.timer
+%{_unitdir}/cron-quarterly.service
+%{_unitdir}/cron-quarterly.target
+%{_unitdir}/cron-quarterly.timer
+%{_unitdir}/cron-semi-annually.service
+%{_unitdir}/cron-semi-annually.target
+%{_unitdir}/cron-semi-annually.timer
+%{_unitdir}/cron-update.path
+%{_unitdir}/cron-update.service
+%{_unitdir}/cron-weekly.service
+%{_unitdir}/cron-weekly.target
+%{_unitdir}/cron-weekly.timer
+%{_unitdir}/cron-yearly.service
+%{_unitdir}/cron-yearly.target
+%{_unitdir}/cron-yearly.timer
+%{_unitdir}/cron.target
+%{_presetdir}/50-systemd-cron.preset
+%dir %{_prefix}/lib/systemd-cron
+%{_prefix}/lib/systemd-cron/boot_delay
+%attr(2755,root,crontab) %{_prefix}/lib/systemd-cron/crontab_setgid
+%{_prefix}/lib/systemd-cron/mail_on_failure
+%{_prefix}/lib/systemd-cron/remove_stale_stamps
+%{_systemdgeneratordir}/systemd-crontab-generator
+%{_sysusersdir}/systemd-cron.conf
+%attr(0770,root,crontab) %dir /var/spool/cron
+%{_mandir}/man1/crontab.1*
+%{_mandir}/man5/anacrontab.5*
+%{_mandir}/man5/crontab.5*
+%{_mandir}/man7/systemd.cron.7*
+%{_mandir}/man8/systemd-crontab-generator.8*
+%doc LICENSE
+
+%changelog
+* Thu Mar 25 2021 Silvan Calarco <silvan.calarco@mambasoft.it> 1.5.17-2mamba
+- workaround cron-failure not sending email by unsetting DynamicUser=yes
+
+* Fri Mar 05 2021 Silvan Calarco <silvan.calarco@mambasoft.it> 1.5.17-1mamba
+- package created using the webbuild interface