diff --git a/include/ccnx-closure.h b/include/ccnx-closure.h
index 66f79e8..f006d11 100644
--- a/include/ccnx-closure.h
+++ b/include/ccnx-closure.h
@@ -31,6 +31,9 @@
   virtual TimeoutCallbackReturnValue
   runTimeoutCallback(const Name &interest);
 
+  virtual Closure *
+  dup() const;
+
 protected:
   int m_retry;
   TimeoutCallback *m_timeoutCallback;