diff --git a/daemon/rib/service.cpp b/daemon/rib/service.cpp
index 0c674b3..d850ed2 100644
--- a/daemon/rib/service.cpp
+++ b/daemon/rib/service.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2021,  Regents of the University of California,
+ * Copyright (c) 2014-2022,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -43,8 +43,6 @@
 
 NFD_LOG_INIT(RibService);
 
-Service* Service::s_instance = nullptr;
-
 const std::string CFG_RIB = "rib";
 const std::string CFG_LOCALHOST_SECURITY = "localhost_security";
 const std::string CFG_LOCALHOP_SECURITY = "localhop_security";
@@ -52,8 +50,8 @@
 const std::string CFG_PREFIX_PROPAGATE = "auto_prefix_propagate";
 const std::string CFG_READVERTISE_NLSR = "readvertise_nlsr";
 const Name READVERTISE_NLSR_PREFIX = "/localhost/nlsr";
-const uint64_t PROPAGATE_DEFAULT_COST = 15;
-const time::milliseconds PROPAGATE_DEFAULT_TIMEOUT = 10_s;
+constexpr uint64_t PROPAGATE_DEFAULT_COST = 15;
+constexpr time::milliseconds PROPAGATE_DEFAULT_TIMEOUT = 10_s;
 
 static ConfigSection
 loadConfigSectionFromFile(const std::string& filename)
@@ -64,10 +62,7 @@
   return config;
 }
 
-/**
- * \brief Look into the config file and construct appropriate transport to communicate with NFD
- * If NFD-RIB instance was initialized with config file, INFO format is assumed
- */
+// Look into NFD's config file and construct an appropriate transport to communicate with NFD.
 static shared_ptr<ndn::Transport>
 makeLocalNfdTransport(const ConfigSection& config)
 {