diff --git a/lib/http/server.js b/lib/http/server.js
index 9f73afbe..b3c888ca 100644
--- a/lib/http/server.js
+++ b/lib/http/server.js
@@ -550,10 +550,7 @@ HTTPServer.prototype._init = function _init() {
 
       enforce(Array.isArray(cmd.params), 'Params must be an array.');
 
-      if (!cmd.id)
-        cmd.id = 0;
-
-      enforce(typeof cmd.id === 'number', 'ID must be a number.');
+      enforce(!cmd.id || typeof cmd.id !== 'object', 'Invalid ID.');
     }
 
     for (i = 0; i < cmds.length; i++) {