diff --git a/src/protocol-detail/new-renew-revoke.cpp b/src/protocol-detail/new-renew-revoke.cpp
index 9d6f5f8..b368c8c 100644
--- a/src/protocol-detail/new-renew-revoke.cpp
+++ b/src/protocol-detail/new-renew-revoke.cpp
@@ -97,6 +97,7 @@
   content.parse();
   const auto& ecdhKey = readString(content.get(tlv_ecdh_pub));
   const auto& salt = readString(content.get(tlv_salt));
+  uint64_t saltInt = std::stoull(salt);
   const auto& requestStatus = static_cast<Status>(readNonNegativeInteger(content.get(tlv_status)));
   const auto& requestId = readString(content.get(tlv_request_id));
   std::list<std::string> challenges;
@@ -105,7 +106,7 @@
       challenges.push_back(readString(element));
     }
   }
-  return DecodedData{ecdhKey, salt, requestId, requestStatus, challenges};
+  return DecodedData{ecdhKey, saltInt, requestId, requestStatus, challenges};
 }
 
 }  // namespace ndncert
diff --git a/src/protocol-detail/new-renew-revoke.hpp b/src/protocol-detail/new-renew-revoke.hpp
index 86c46d0..de5d558 100644
--- a/src/protocol-detail/new-renew-revoke.hpp
+++ b/src/protocol-detail/new-renew-revoke.hpp
@@ -40,7 +40,7 @@
                              const std::list<std::string>& challenges);
   struct DecodedData {
     std::string ecdhKey;
-    std::string salt;
+    uint64_t salt;
     std::string requestId;
     Status requestStatus;
     std::list<std::string> challenges;