diff --git a/src/contact-manager.hpp b/src/contact-manager.hpp
index b475eb4..456a19d 100644
--- a/src/contact-manager.hpp
+++ b/src/contact-manager.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
 /*
- * Copyright (c) 2013, Regents of the University of California
+ * Copyright (c) 2020, Regents of the University of California
  *                     Yingdi Yu
  *
  * BSD license, See the LICENSE file for more information
@@ -256,7 +256,8 @@
 
 private:
 
-  class FetchedInfo {
+  class FetchedInfo
+  {
   public:
     shared_ptr<EndorseCertificate> m_selfEndorseCert;
     shared_ptr<EndorseCollection> m_endorseCollection;
@@ -283,9 +284,9 @@
   BufferedIdCerts m_bufferedIdCerts;
 
   // Tmp Dns
-  shared_ptr<ndn::RegisteredPrefixHandle> m_dnsListenerId;
-  shared_ptr<ndn::RegisteredPrefixHandle> m_keyListenerId;
-  shared_ptr<ndn::RegisteredPrefixHandle> m_profileCertListenerId;
+  ndn::ScopedRegisteredPrefixHandle m_dnsListenerHandle;
+  ndn::ScopedRegisteredPrefixHandle m_keyListenerHandle;
+  ndn::ScopedRegisteredPrefixHandle m_profileCertListenerHandle;
 
   RecLock m_collectCountMutex;
   size_t m_collectCount;