diff --git a/libnm-core/nm-setting-ip-config.c b/libnm-core/nm-setting-ip-config.c
index 9e3a9fb14c..83af52f1e0 100644
--- a/libnm-core/nm-setting-ip-config.c
+++ b/libnm-core/nm-setting-ip-config.c
@@ -83,8 +83,15 @@ canonicalize_ip (int family, const char *ip, gboolean null_any)
 	char addr_str[NM_UTILS_INET_ADDRSTRLEN];
 	int ret;
 
-	if (!ip)
-		return NULL;
+	if (!ip) {
+		if (null_any)
+			return NULL;
+		if (family == AF_INET)
+			return g_strdup ("0.0.0.0");
+		if (family == AF_INET6)
+			return g_strdup ("::");
+		g_return_val_if_reached (NULL);
+	}
 
 	ret = inet_pton (family, ip, addr_bytes);
 	g_return_val_if_fail (ret == 1, NULL);
@@ -599,6 +606,7 @@ nm_ip_route_new (int family,
 	NMIPRoute *route;
 
 	g_return_val_if_fail (family == AF_INET || family == AF_INET6, NULL);
+	g_return_val_if_fail (dest, NULL);
 
 	if (!valid_ip (family, dest, error))
 		return NULL;
@@ -645,7 +653,6 @@ nm_ip_route_new_binary (int family,
                         GError **error)
 {
 	NMIPRoute *route;
-	char string[NM_UTILS_INET_ADDRSTRLEN];
 
 	g_return_val_if_fail (family == AF_INET || family == AF_INET6, NULL);
 	g_return_val_if_fail (dest, NULL);
@@ -659,7 +666,7 @@ nm_ip_route_new_binary (int family,
 	route->refcount = 1;
 
 	route->family = family;
-	route->dest = g_strdup (inet_ntop (family, dest, string, sizeof (string)));
+	route->dest = canonicalize_ip_binary (family, dest, FALSE);
 	route->prefix = prefix;
 	route->next_hop = canonicalize_ip_binary (family, next_hop, TRUE);
 	route->metric = metric;
@@ -814,17 +821,11 @@ void
 nm_ip_route_set_dest (NMIPRoute *route,
                       const char *dest)
 {
-	char *new_dest;
-
 	g_return_if_fail (route != NULL);
-	g_return_if_fail (dest != NULL);
 	g_return_if_fail (nm_utils_ipaddr_valid (route->family, dest));
 
-	new_dest = canonicalize_ip (route->family, dest, FALSE);
-	g_return_if_fail (new_dest);
-
 	g_free (route->dest);
-	route->dest = new_dest;
+	route->dest = canonicalize_ip (route->family, dest, FALSE);
 }
 
 /**
@@ -2334,7 +2335,7 @@ set_property (GObject *object, guint prop_id,
 		gateway = g_value_get_string (value);
 		g_return_if_fail (!gateway || nm_utils_ipaddr_valid (NM_SETTING_IP_CONFIG_GET_FAMILY (setting), gateway));
 		g_free (priv->gateway);
-		priv->gateway = canonicalize_ip (NM_SETTING_IP_CONFIG_GET_FAMILY (setting), gateway, FALSE);
+		priv->gateway = canonicalize_ip (NM_SETTING_IP_CONFIG_GET_FAMILY (setting), gateway, TRUE);
 		break;
 	case PROP_ROUTES:
 		g_ptr_array_unref (priv->routes);