diff --git a/tcpdump.spec b/tcpdump.spec
index dec3285..7798730 100644
--- a/tcpdump.spec
+++ b/tcpdump.spec
@@ -2,12 +2,13 @@ Summary: A network traffic monitoring tool
 Name: tcpdump
 Epoch: 14
 Version: 3.9.8
-Release: 4%{?dist}
+Release: 5%{?dist}
 License: BSD with advertising
 URL: http://www.tcpdump.org
 Group: Applications/Internet
 Requires(pre): shadow-utils 
 BuildRequires: openssl-devel libpcap-devel
+BuildRequires: automake
 BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 
 Source0: http://www.tcpdump.org/release/tcpdump-%{version}.tar.gz
@@ -47,9 +48,11 @@ popd
 find . -name '*.c' -o -name '*.h' | xargs chmod 644
 
 %build
-export CFLAGS="$RPM_OPT_FLAGS $(getconf LFS_CFLAGS) -D_GNU_SOURCE"
+export CFLAGS="$RPM_OPT_FLAGS $(getconf LFS_CFLAGS)"
 
 pushd %{tcpslice_dir}
+# update config.{guess,sub}
+automake -a -f 2> /dev/null || :
 %configure
 make %{?_smp_mflags}
 popd
@@ -93,6 +96,10 @@ exit 0
 %{_mandir}/man8/tcpdump.8*
 
 %changelog
+* Mon Jun 02 2008 Miroslav Lichvar <mlichvar@redhat.com> - 14:3.9.8-5
+- update config.{guess,sub} when building tcpslice
+- remove -D_GNU_SOURCE from CFLAGS
+
 * Wed Feb 13 2008 Miroslav Lichvar <mlichvar@redhat.com> - 14:3.9.8-4
 - fix building with new glibc headers