diff --git a/ndn-cpp/fields/blob.h b/ndn-cpp/fields/blob.h
index 85fd71b..ce0d667 100644
--- a/ndn-cpp/fields/blob.h
+++ b/ndn-cpp/fields/blob.h
@@ -15,9 +15,14 @@
 
 #include <vector>
 #include <cstddef>
+#include <boost/shared_ptr.hpp>
 
 namespace ndn {
 
+class Blob;
+typedef boost::shared_ptr<Blob> BlobPtr;
+typedef boost::shared_ptr<const Blob> ConstBlobPtr;
+
 /**
  * @brief Class representing a general-use binary blob
  */
diff --git a/ndn-cpp/fields/name.h b/ndn-cpp/fields/name.h
index 18e2412..a356f8f 100644
--- a/ndn-cpp/fields/name.h
+++ b/ndn-cpp/fields/name.h
@@ -18,6 +18,10 @@
 
 namespace ndn {
 
+class Name;
+typedef boost::shared_ptr<Name> NamePtr;
+typedef boost::shared_ptr<const Name> ConstNamePtr;
+
 /**
  * @brief Class for NDN Name
  */
@@ -393,8 +397,6 @@
   std::vector<name::Component> m_comps;
 };
 
-typedef boost::shared_ptr<Name> NamePtr;
-
 inline std::ostream &
 operator << (std::ostream &os, const Name &name)
 {
diff --git a/ndn-cpp/fields/signature.h b/ndn-cpp/fields/signature.h
index a9fb39a..1368663 100644
--- a/ndn-cpp/fields/signature.h
+++ b/ndn-cpp/fields/signature.h
@@ -12,11 +12,16 @@
 #define NDN_SIGNATURE_H
 
 #include <iostream>
+#include <boost/shared_ptr.hpp>
 
 namespace ndn {
 
 namespace wire { class Base; }
 
+class Signature;
+typedef boost::shared_ptr<Signature> SignaturePtr;
+typedef boost::shared_ptr<const Signature> ConstSignaturePtr;
+
 /**
  * @brief Pure virtual class providing an interface to work with signatures for NDN data packets
  */
diff --git a/ndn-cpp/fields/signed-blob.h b/ndn-cpp/fields/signed-blob.h
index 2686977..fd5bf90 100644
--- a/ndn-cpp/fields/signed-blob.h
+++ b/ndn-cpp/fields/signed-blob.h
@@ -17,6 +17,10 @@
 
 namespace ndn {
 
+class SignedBlob;
+typedef boost::shared_ptr<SignedBlob> SignedBlobPtr;
+typedef boost::shared_ptr<const SignedBlob> ConstSignedBlobPtr;
+
 /**
  * @brief Class representing a blob, which has a signed portion (e.g., bytes of DATA packet)
  */
@@ -92,7 +96,6 @@
   return m_signedEnd - m_signedBegin;
 }
 
-
 } // ndn
 
 #endif // NDN_SIGNED_BLOB_H