diff --git a/wireguard-ipv6/root/etc/s6-overlay/s6-rc.d/init-wireguard-confs/run b/wireguard-ipv6/root/etc/s6-overlay/s6-rc.d/init-wireguard-confs/run
index 2a57c4f..f107e02 100755
--- a/wireguard-ipv6/root/etc/s6-overlay/s6-rc.d/init-wireguard-confs/run
+++ b/wireguard-ipv6/root/etc/s6-overlay/s6-rc.d/init-wireguard-confs/run
@@ -59,7 +59,7 @@ DUDE"
           fi
         done
         for idx in {2..254}; do
-          PROPOSED_IPV6="${INTERFACE_IPV6}.${idx}"
+          PROPOSED_IPV6="${INTERFACE_IPV6}:${idx}"
           if ! grep -q -R "${PROPOSED_IPV6}" /config/peer*/*.conf 2>/dev/null && ([ -z "${ORIG_INTERFACE}" ] || ! grep -q -R "${ORIG_INTERFACE}.${idx}" /config/peer*/*.conf 2>/dev/null); then
             CLIENT_IPV6="${PROPOSED_IPV6}"
             break