diff --git a/src/factory/WFTask.h b/src/factory/WFTask.h
index 25821d08..29a704db 100644
--- a/src/factory/WFTask.h
+++ b/src/factory/WFTask.h
@@ -473,7 +473,7 @@ protected:
 class WFMailboxTask : public WFGenericTask
 {
 public:
-	void send(void *msg)
+	virtual void send(void *msg)
 	{
 		*this->mailbox = msg;
 		if (this->flag.exchange(true))