diff --git a/weed/command/server.go b/weed/command/server.go
index 63133b80c..503927629 100644
--- a/weed/command/server.go
+++ b/weed/command/server.go
@@ -119,6 +119,7 @@ func init() {
 	filerOptions.downloadMaxMBps = cmdServer.Flag.Int("filer.downloadMaxMBps", 0, "download max speed for each download request, in MB per second")
 	filerOptions.diskType = cmdServer.Flag.String("filer.disk", "", "[hdd|ssd|<tag>] hard drive or solid state drive or any tag")
 	filerOptions.exposeDirectoryData = cmdServer.Flag.Bool("filer.exposeDirectoryData", true, "expose directory data via filer. If false, filer UI will be innaccessible.")
+	filerOptions.joinExistingFiler = cmdServer.Flag.Bool("filer.joinExistingFiler", false, "enable if new filer wants to join existing cluster")
 
 	serverOptions.v.port = cmdServer.Flag.Int("volume.port", 8080, "volume server http listen port")
 	serverOptions.v.portGrpc = cmdServer.Flag.Int("volume.port.grpc", 0, "volume server grpc listen port")