diff --git a/nameserver/http.go b/nameserver/http.go
index 29311d4c..5cd70f5a 100644
--- a/nameserver/http.go
+++ b/nameserver/http.go
@@ -35,6 +35,11 @@ func (n *Nameserver) HandleHTTP(router *mux.Router, dockerCli *docker.Client) {
 			return
 		}
 
+		if !dns.IsSubDomain(n.domain, hostname) {
+			n.infof("Ignoring registration %s %s %s (not a subdomain of %s)", hostname, ipStr, container, n.domain)
+			return
+		}
+
 		if err := n.AddEntry(hostname, container, n.ourName, ip); err != nil {
 			n.badRequest(w, fmt.Errorf("Unable to add entry: %v", err))
 			return
diff --git a/proxy/common.go b/proxy/common.go
index 1dfe787e..29db23ef 100644
--- a/proxy/common.go
+++ b/proxy/common.go
@@ -21,6 +21,7 @@ var (
 	containerIDRegexp   = regexp.MustCompile("^(/v[0-9\\.]*)?/containers/([^/]*)/.*")
 	weaveWaitEntrypoint = []string{"/w/w"}
 	weaveEntrypoint     = "/home/weave/weaver"
+	weaveContainerName  = "/weave"
 )
 
 func callWeave(args ...string) ([]byte, []byte, error) {
diff --git a/proxy/proxy.go b/proxy/proxy.go
index dc6bcfcf..f087d769 100644
--- a/proxy/proxy.go
+++ b/proxy/proxy.go
@@ -315,7 +315,8 @@ func containerShouldAttach(container *docker.Container) bool {
 }
 
 func containerIsWeaveRouter(container *docker.Container) bool {
-	return len(container.Config.Entrypoint) > 0 && container.Config.Entrypoint[0] == weaveEntrypoint
+	return container.Name == weaveContainerName &&
+		len(container.Config.Entrypoint) > 0 && container.Config.Entrypoint[0] == weaveEntrypoint
 }
 
 func (proxy *Proxy) createWait(r *http.Request, ident string) {