diff --git a/.gitignore b/.gitignore
index baf7e95..fe50133 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 /chrony-1.30-pre1.tar.gz
+/clknetsim-d5a9a5.tar.gz
diff --git a/chrony.spec b/chrony.spec
index 2bc9e36..99895b8 100644
--- a/chrony.spec
+++ b/chrony.spec
@@ -19,6 +19,8 @@ Source5:        chrony.logrotate
 Source7:        chrony.nm-dispatcher
 Source8:        chrony.dhclient
 Source9:        chrony-wait.service
+# simulator for test suite from https://github.com/mlichvar/clknetsim.git
+Source10:       clknetsim-d5a9a5.tar.gz
 %{?gitpatch:Patch0: chrony-%{version}%{?prerelease}-%{gitpatch}.patch.gz}
 
 BuildRequires:  libcap-devel libedit-devel nss-devel pps-tools-devel
@@ -42,7 +44,7 @@ clocks, system real-time clock or manual input as time references.
 %endif
 
 %prep
-%setup -q -n %{name}-%{version}%{?prerelease}
+%setup -q -n %{name}-%{version}%{?prerelease} -a 10
 %{?gitpatch:%patch0 -p1}
 
 %{?gitpatch: echo %{version}-%{gitpatch} > version.txt}
@@ -50,6 +52,8 @@ clocks, system real-time clock or manual input as time references.
 sed -e 's|VENDORZONE\.|%{vendorzone}|' < %{SOURCE1} > chrony.conf
 touch -r %{SOURCE1} chrony.conf
 
+mv clknetsim test/simulation
+
 %build
 %configure \
 %{?with_debug: --enable-debug} \
@@ -86,6 +90,10 @@ touch $RPM_BUILD_ROOT%{_localstatedir}/lib/chrony/{drift,rtc}
 echo 'chronyd.service' > \
         $RPM_BUILD_ROOT%{_prefix}/lib/systemd/ntp-units.d/50-chronyd.list
 
+%check
+make %{?_smp_mflags} -C test/simulation/clknetsim
+make check
+
 %pre
 getent group chrony > /dev/null || /usr/sbin/groupadd -r chrony
 getent passwd chrony > /dev/null || /usr/sbin/useradd -r -g chrony \
diff --git a/sources b/sources
index f44f5ff..274b49c 100644
--- a/sources
+++ b/sources
@@ -1 +1,2 @@
 3df633d4964d7e92f38fac68ef544d84  chrony-1.30-pre1.tar.gz
+ad8f551e14136f3854d97f994f92a64e  clknetsim-d5a9a5.tar.gz