diff --git a/Lib/ipaddress.py b/Lib/ipaddress.py
index 25bcccd..bf4e01e 100644
--- a/Lib/ipaddress.py
+++ b/Lib/ipaddress.py
@@ -578,6 +578,10 @@
     def __repr__(self):
         return '%s(%r)' % (self.__class__.__name__, str(self))
 
+    def __str__(self):
+        return '%s/%d' % (str(self.network_address),
+                          self.prefixlen)
+
     def hosts(self):
         """Generate Iterator over usable hosts in a network.
 
@@ -663,9 +667,6 @@
             return NotImplemented
         return not eq
 
-    def __str__(self):
-        return '%s/%s' % (self.ip, self._prefixlen)
-
     def __hash__(self):
         return hash(int(self.network_address) ^ int(self.netmask))
 
@@ -708,15 +709,15 @@
 
     @property
     def with_prefixlen(self):
-        return '%s/%d' % (str(self.ip), self._prefixlen)
+        return '%s/%d' % (str(self.network_address), self._prefixlen)
 
     @property
     def with_netmask(self):
-        return '%s/%s' % (str(self.ip), str(self.netmask))
+        return '%s/%s' % (str(self.network_address), str(self.netmask))
 
     @property
     def with_hostmask(self):
-        return '%s/%s' % (str(self.ip), str(self.hostmask))
+        return '%s/%s' % (str(self.network_address), str(self.hostmask))
 
     @property
     def num_addresses(self):
@@ -1447,10 +1448,6 @@
         """The binary representation of this address."""
         return v4_int_to_packed(self.network_address)
 
-    def __str__(self):
-        return '%s/%d' % (str(self.network_address),
-                          self.prefixlen)
-
     def _is_valid_netmask(self, netmask):
         """Verify that the netmask is valid.
 
@@ -1498,18 +1495,6 @@
             return True
         return False
 
-    @property
-    def with_prefixlen(self):
-        return '%s/%d' % (str(self.network_address), self._prefixlen)
-
-    @property
-    def with_netmask(self):
-        return '%s/%s' % (str(self.network_address), str(self.netmask))
-
-    @property
-    def with_hostmask(self):
-        return '%s/%s' % (str(self.network_address), str(self.hostmask))
-
 
 class _BaseV6:
 
@@ -2108,10 +2093,6 @@
         if self._prefixlen == (self._max_prefixlen - 1):
             self.hosts = self.__iter__
 
-    def __str__(self):
-        return '%s/%d' % (str(self.network_address),
-                          self.prefixlen)
-
     def _is_valid_netmask(self, prefixlen):
         """Verify that the netmask/prefixlen is valid.
 
@@ -2128,15 +2109,3 @@
         except ValueError:
             return False
         return 0 <= prefixlen <= self._max_prefixlen
-
-    @property
-    def with_prefixlen(self):
-        return '%s/%d' % (str(self.network_address), self._prefixlen)
-
-    @property
-    def with_netmask(self):
-        return '%s/%s' % (str(self.network_address), str(self.netmask))
-
-    @property
-    def with_hostmask(self):
-        return '%s/%s' % (str(self.network_address), str(self.hostmask))
diff --git a/Lib/test/test_ipaddress.py b/Lib/test/test_ipaddress.py
index 5b7d013..17c32f2 100644
--- a/Lib/test/test_ipaddress.py
+++ b/Lib/test/test_ipaddress.py
@@ -972,6 +972,22 @@
         self.assertTrue(self.ipv4_address in dummy)
         self.assertTrue(ip2 in dummy)
 
+    def testIPv6NetworkHelpers(self):
+        net = self.ipv6_network
+        self.assertEqual('2001:658:22a:cafe::/64', net.with_prefixlen)
+        self.assertEqual('2001:658:22a:cafe::/ffff:ffff:ffff:ffff::',
+                         net.with_netmask)
+        self.assertEqual('2001:658:22a:cafe::/::ffff:ffff:ffff:ffff',
+                         net.with_hostmask)
+        self.assertEqual('2001:658:22a:cafe::/64', str(net))
+
+    def testIPv4NetworkHelpers(self):
+        net = self.ipv4_network
+        self.assertEqual('1.2.3.0/24', net.with_prefixlen)
+        self.assertEqual('1.2.3.0/255.255.255.0', net.with_netmask)
+        self.assertEqual('1.2.3.0/0.0.0.255', net.with_hostmask)
+        self.assertEqual('1.2.3.0/24', str(net))
+
     def testCopyConstructor(self):
         addr1 = ipaddress.ip_network('10.1.1.0/24')
         addr2 = ipaddress.ip_network(addr1)