diff --git a/acconfig.h b/acconfig.h
index 289f046..1f61dbe 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -26,6 +26,9 @@
 /* Define this if you are using Mesa */
 #undef XMESA
 
+/* Define this if you want IPv6 support */
+#undef HAVE_IPV6
+
 /* Define this if you have GL_COLOR_INDEX8_EXT in GL/gl.h */
 #undef HAVE_GL_COLOR_INDEX8_EXT
 
diff --git a/configure.in b/configure.in
index dfa4cd9..ee7bc99 100644
--- a/configure.in
+++ b/configure.in
@@ -69,7 +69,7 @@ AC_FUNC_MMAP
 AC_FUNC_VPRINTF
 AC_CHECK_FUNCS(gethostname gethostbyname connect gettimeofday getwd mkdir \
 	ftime _ftime fcntl stat putenv select socket strerror strstr \
-	snprintf _snprintf vsnprintf _vsnprintf strsep dlopen)
+	snprintf _snprintf vsnprintf _vsnprintf strsep dlopen getaddrinfo getnameinfo)
 
 AC_ARG_ENABLE(experimental,
 [  --enable-experimental  compile with experimental code. Use at your
@@ -97,6 +97,14 @@ AC_ARG_ENABLE(release,
        RELEASE=$enable_release
 )
 
+AC_ARG_ENABLE(ipv6,
+[  --enable-ipv6           enable IPv6 support],
+	AC_DEFINE(HAVE_IPV6)
+	NET_SOURCE=net_udp6.c
+,
+	NET_SOURCE=net_udp.c
+)
+
 AC_ARG_ENABLE(alsa,
 [  --enable-alsa           enable alsa support],
 )	
@@ -785,6 +793,7 @@ AC_SUBST(QW_SRV_SYS_SRC)
 AC_SUBST(X11_VID_SRC)
 AC_SUBST(HAVE_WSOCK)
 AC_SUBST(HAVE_UDP)
+AC_SUBST(NET_SOURCE)
 AC_SUBST(VERSION)
 AC_SUBST(QF_VERSION)
 
diff --git a/qw_client/Makefile.in b/qw_client/Makefile.in
index feb3eb6..56bb6a1 100644
--- a/qw_client/Makefile.in
+++ b/qw_client/Makefile.in
@@ -137,11 +137,8 @@ CD_AUDIO_SRC   = cd_wrapper.c
 SYS_SRC        = sys_common.c @QW_CL_SYS_SRC@
 
 # Networking source files
-#
-# Uncomment the second line to add IPv6 support
 
-QW_NET_SRC     = net_udp.c net_com.c mdfour.c
-#QW_NET_SRC	= net_udp6.c net_com.c mdfour.c
+QW_NET_SRC     = @NET_SOURCE@ net_com.c mdfour.c
 
 # Common source files
 
diff --git a/qw_server/Makefile.in b/qw_server/Makefile.in
index b4a25f9..b2f2116 100644
--- a/qw_server/Makefile.in
+++ b/qw_server/Makefile.in
@@ -39,11 +39,8 @@ QW_SRV_SYS_SRC = sys_common.c @QW_SRV_SYS_SRC@
 
 # Networking source files
 # FIXME: Should not assume UNIX
-#
-# Uncomment the second line for IPv6 support 
 
-QW_NET_SRC     = net_udp.c net_com.c mdfour.c
-#QW_NET_SRC	= net_udp6.c net_com.c mdfour.c
+QW_NET_SRC     = @NET_SOURCE@ net_com.c mdfour.c
 
 # Server source files