--- a/js/ipc/CPOWTypes.h
+++ b/js/ipc/CPOWTypes.h
@@ -39,23 +39,23 @@
  * ***** END LICENSE BLOCK ***** */
 
 #ifndef mozilla_jsipc_ContextWrapperTypes_h__
 #define mozilla_jsipc_ContextWrapperTypes_h__
 
 #include "jsapi.h"
 #include "jspubtd.h"
 
+using mozilla::void_t;
+
 namespace mozilla {
 namespace jsipc {
 
 using namespace IPC;
 
-struct void_t {};
-
 template <typename P>
 struct CPOWSingleton
 {
     static void Write(Message*, const P&) {}
     static bool Read(const Message*, void**, P*) { return true; }
 };
 
 template <typename Type, typename As>
@@ -73,17 +73,16 @@ struct CPOWConvertible
 
 } // namespace jsipc
 } // namespace mozilla
 
 namespace IPC {
 
 using namespace mozilla::jsipc;
 
-template <> struct ParamTraits<void_t> : public CPOWSingleton<void_t> {};
 template <> struct ParamTraits<JSType> : public CPOWConvertible<JSType, int> {};
 
 }
 
 // TODO Use a more standard logging mechanism.
 #ifdef LOGGING
 #define CPOW_LOG(PRINTF_ARGS) \
     JS_BEGIN_MACRO            \