diff --git a/quagga.spec b/quagga.spec
index effdef1..f9df184 100644
--- a/quagga.spec
+++ b/quagga.spec
@@ -6,6 +6,7 @@
 %define		with_tcp_zebra	0
 %define		with_pam	0
 %define		with_ipv6	1
+%define		with_isisd	1
 %define		with_ospfclient 1
 %define		with_ospfapi	1
 %define         with_rtadv      1
@@ -140,6 +141,9 @@ export CXXFLAGS="$RPM_OPT_FLAGS $CPPFLAGS"
 %else
 	--enable-ipv6=no \
 %endif
+%if %with_isisd
+	--enable-isisd=yes \
+%endif
 %if %with_snmp
 	--enable-snmp=yes \
 %endif
@@ -207,7 +211,9 @@ make install \
 rm -rf $RPM_BUILD_ROOT/usr/share/info/dir
 
 install -m 644 %{zeb_rh_src}/zebra.service $RPM_BUILD_ROOT/lib/systemd/system
+%if %with_isisd
 install -m 644 %{zeb_rh_src}/isisd.service $RPM_BUILD_ROOT/lib/systemd/system
+%endif
 install -m 644 %{zeb_rh_src}/ripd.service $RPM_BUILD_ROOT/lib/systemd/system
 install -m 644 %{zeb_rh_src}/ospfd.service $RPM_BUILD_ROOT/lib/systemd/system
 install -m 644 %{zeb_rh_src}/bgpd.service $RPM_BUILD_ROOT/lib/systemd/system
@@ -218,7 +224,9 @@ install -m 644 %{zeb_rh_src}/ripngd.service $RPM_BUILD_ROOT/lib/systemd/system
 %endif
 
 install %{zeb_rh_src}/zebra.init $RPM_BUILD_ROOT/etc/rc.d/init.d/zebra
+%if %with_isisd
 install %{zeb_rh_src}/isisd.init $RPM_BUILD_ROOT/etc/rc.d/init.d/isisd
+%endif
 install %{zeb_rh_src}/bgpd.init $RPM_BUILD_ROOT/etc/rc.d/init.d/bgpd
 %if %with_ipv6
 install %{zeb_rh_src}/ospf6d.init $RPM_BUILD_ROOT/etc/rc.d/init.d/ospf6d
@@ -294,8 +302,10 @@ if [ "$1" = "0" ]; then
 	/bin/systemctl stop bgpd.service > /dev/null 2>&1 || :
 	/bin/systemctl disable zebra.service > /dev/null 2>&1 || :
 	/bin/systemctl stop zebra.service > /dev/null 2>&1 || :
+%if %with_isisd
 	/bin/systemctl disable isisd.service > /dev/null 2>&1 || :
 	/bin/systemctl stop isisd.service > /dev/null 2>&1 || :
+%endif
 	/bin/systemctl disable ospfd.service > /dev/null 2>&1 || :
 	/bin/systemctl stop ospfd.service > /dev/null 2>&1 || :
 	/bin/systemctl disable watchquagga.service > /dev/null 2>&1 || :
@@ -310,6 +320,9 @@ fi
 
 %triggerun --  %{name} < 0.99.18-6
 	/sbin/chkconfig --del zebra >/dev/null 2>&1 || :
+%if !%with_isisd
+	/sbin/service isisd stop >/dev/null 2>&1 || :
+%endif
 	/sbin/chkconfig --del isisd >/dev/null 2>&1 || :
 	/sbin/chkconfig --del ripd >/dev/null 2>&1 || :
 	/sbin/chkconfig --del bgpd >/dev/null 2>&1 || :
@@ -322,7 +335,9 @@ fi
 	/sbin/chkconfig --del ospf6d >/dev/null 2>&1 || :
 	/sbin/chkconfig --del ripngd >/dev/null 2>&1 || :
 	/bin/systemctl try-restart zebra.service >/dev/null 2>&1 || :
+%if %with_isisd
 	/bin/systemctl try-restart isisd.service >/dev/null 2>&1 || :
+%endif
 	/bin/systemctl try-restart ripd.service >/dev/null 2>&1 || :
 	/bin/systemctl try-restart bgpd.service >/dev/null 2>&1 || :
 	/bin/systemctl try-restart ospfd.service >/dev/null 2>&1 || :
@@ -334,7 +349,9 @@ fi
 
 %triggerpostun -n %{name}-sysvinit -- %{name} < 0.99.18-6
 	/sbin/chkconfig --add zebra >/dev/null 2>&1 || :
+%if %with_isisd
 	/sbin/chkconfig --add isisd >/dev/null 2>&1 || :
+%endif
 	/sbin/chkconfig --add ripd >/dev/null 2>&1 || :
 	/sbin/chkconfig --add bgpd >/dev/null 2>&1 || :
 	/sbin/chkconfig --add ospfd >/dev/null 2>&1 || :