diff --git a/lib/transports/xhr-polling.js b/lib/transports/xhr-polling.js
index 289febeba..1d05fe117 100644
--- a/lib/transports/xhr-polling.js
+++ b/lib/transports/xhr-polling.js
@@ -31,6 +31,12 @@
 
   io.util.inherit(XHRPolling, io.Transport.XHR);
 
+  /**
+   * Merge the properties from XHR transport
+   */
+
+  io.util.merge(XHRPolling, io.Transport.XHR);
+
   /**
    * Transport name
    *