Should use references to shared_ptr
diff --git a/ndn-cpp/NDN.cpp b/ndn-cpp/NDN.cpp
index cd1dbe6..cafa4c6 100644
--- a/ndn-cpp/NDN.cpp
+++ b/ndn-cpp/NDN.cpp
@@ -20,7 +20,8 @@
     ptr_lib::shared_ptr<ContentObject> contentObject(new ContentObject());
     contentObject->decode(element, elementLength);
     
-    UpcallInfo upcallInfo(this, ptr_lib::shared_ptr<Interest>(), 0, contentObject);
+    ptr_lib::shared_ptr<Interest> dummyInterest;
+    UpcallInfo upcallInfo(this, dummyInterest, 0, contentObject);
     closure_->upcall(UPCALL_CONTENT, upcallInfo);
   }
 }