diff --git a/configure.in b/configure.in
index cff5a6c8..dacbedb7 100644
--- a/configure.in
+++ b/configure.in
@@ -42,7 +42,7 @@ fi
 
 AC_ARG_WITH( openssl, [  --with-openssl=/path/to/openssl], OPENSSL=$withval,)
 AC_ARG_ENABLE( debug, [  --enable-debug  enable debuging], appendCXX -Wall -ggdb -D_DEBUG, appendCXX -Wall -s -O2 -fomit-frame-pointer )
-AC_ARG_ENABLE( ipv6, [  --enable-ipv6  enable ipv6 support], -DHAVE_IPV6,)
+AC_ARG_ENABLE( ipv6, [  --enable-ipv6  enable ipv6 support], appendCXX -DHAVE_IPV6,)
 AC_ARG_ENABLE( modules, [  --disable-modules  disable modules], MODULES="no", MODULES="yes")
 AC_ARG_ENABLE( openssl, [  --disable-openssl  disable openssl], NOSSL=1,)
 AC_ARG_ENABLE( perl, [  --disable-perl  disable perl], NOPERL=1,)