diff --git a/utils/he_ipv6/tunnelbroker.py b/utils/he_ipv6/tunnelbroker.py
index 06d2e4d..f28cf97 100644
--- a/utils/he_ipv6/tunnelbroker.py
+++ b/utils/he_ipv6/tunnelbroker.py
@@ -148,12 +148,12 @@ class TunnelBroker(object):
                 try:
                     ipr.addr('add',
                              index = assignment.iface_idx,
-                             address = a.ip.str,
-                             mask = a.ip.prefix,
+                             address = a.str,
+                             mask = a.prefix,
                              family = socket.AF_INET6)
                 except Exception as e:
                     logger.error(('Could not add address {0} on link {1}: '
-                                  '{2}').format(str(a.ip.str), assignment.iface_idx, e))
+                                  '{2}').format(a.str, assignment.iface_idx, e))
                     ipr.close()
                     raise e
             # The SLAAC prefixes.
@@ -161,12 +161,12 @@ class TunnelBroker(object):
                 try:
                     ipr.addr('add',
                              index = assignment.iface_idx,
-                             address = str(b.ip),
+                             address = b.str,
                              mask = b.prefixlen,
                              family = socket.AF_INET6)
                 except Exception as e:
                     logger.error(('Could not add address block {0} on link {1}: '
-                                  '{2}').format(str(b), assignment.iface_idx, e))
+                                  '{2}').format(b.str, assignment.iface_idx, e))
                     ipr.close()
                     raise e
         ipr.close()