diff --git a/radvd.spec b/radvd.spec
index 2f871eb..49a8f31 100644
--- a/radvd.spec
+++ b/radvd.spec
@@ -28,16 +28,17 @@ services.
 export CFLAGS="$RPM_OPT_FLAGS -D_GNU_SOURCE -fPIE"
 export LDFLAGS='-Wl,-z,relro,-z,now,-z,noexecstack,-z,nodlopen'
 %configure --with-pidfile=/var/run/radvd/radvd.pid
-make %{?_smp_mflags}
+make 
+# make %{?_smp_mflags} 
+# Parallel builds fail because seds that transform y.tab.x into
+# scanner/gram.x are not executed before compile of scanner/gram.x
 
 %install
 [ $RPM_BUILD_ROOT != "/" ] && rm -rf $RPM_BUILD_ROOT
-
 %makeinstall
 mkdir -p $RPM_BUILD_ROOT%{_sysconfdir}/sysconfig
 mkdir -p $RPM_BUILD_ROOT%{initdir}
 mkdir -p $RPM_BUILD_ROOT/var/run/radvd
-
 install -m 644 radvd.conf.example $RPM_BUILD_ROOT%{_sysconfdir}/radvd.conf
 install -m 755 redhat/radvd.init $RPM_BUILD_ROOT%{initdir}/radvd
 install -m 644 redhat/radvd.sysconfig $RPM_BUILD_ROOT%{_sysconfdir}/sysconfig/radvd