diff --git a/grpc-auth-support.md b/grpc-auth-support.md
index b5ae1d08..36fe0bd0 100644
--- a/grpc-auth-support.md
+++ b/grpc-auth-support.md
@@ -15,9 +15,10 @@ creds, err := credentials.NewServerTLSFromFile(certFile, keyFile)
 if err != nil {
   log.Fatalf("Failed to generate credentials %v", err)
 }
+lis, err := net.Listen("tcp", ":0")
 server := grpc.NewServer(grpc.Creds(creds))
 ...
-server.Serve(creds.NewListener(lis))
+server.Serve(lis)
 ```
 
 # Authenticating with Google