diff --git a/main.go b/main.go
index f156af1..d6b1591 100644
--- a/main.go
+++ b/main.go
@@ -60,7 +60,7 @@ const routingTableTemplate = `
 	<tr>
 		<td>{{$route.NetStart}}{{if not (eq $route.NetStart $route.NetEnd)}} - {{$route.NetEnd}}{{end}}</td>
 		<td>{{if $route.Extended}}✅{{else}}-{{end}}</td>
-		<td>{{range $route.ZoneNames}}{{.}}<br>{{end}}</td>
+		<td>{{range $route.ZoneNames.ToSlice}}{{.}}<br>{{end}}</td>
 		<td>{{$route.Distance}}</td>
 		<td>{{$route.LastSeenAgo}}</td>
 		<td>
diff --git a/router/zones.go b/router/zones.go
index 1dc3ead..42bf81d 100644
--- a/router/zones.go
+++ b/router/zones.go
@@ -29,8 +29,8 @@ func (rt *RouteTable) AddZonesToNetwork(n ddp.Network, zs ...string) {
 		if n < r.NetStart || n > r.NetEnd {
 			continue
 		}
-		if !r.Valid() {
-			continue
+		if r.ZoneNames == nil {
+			r.ZoneNames = make(StringSet)
 		}
 		r.ZoneNames.Insert(zs...)
 	}