diff --git a/utils/he_ipv6.py b/utils/he_ipv6.py
index 4d9b339..b64c39a 100755
--- a/utils/he_ipv6.py
+++ b/utils/he_ipv6.py
@@ -73,8 +73,8 @@ class TunnelBroker(object):
         self.ipr.link('add',
                       ifname = 'he-{0}'.format(self.tun_id),
                       kind = 'sit',
-                      sit_local = self.my_ip,
-                      sit_remote = self.server,
+                      sit_local = str(self.my_ip),
+                      sit_remote = str(self.server),
                       sit_ttl = 255)
         self.iface_idx = self.ipr.link_lookup(ifname = 'he-{0}'.format(self.tun_id))[0]
         self.ipr.link('set', index = self.iface_idx, state = 'up', mtu = 1480)