diff --git a/tests/unit/security/certificate-fetcher-direct-fetch.t.cpp b/tests/unit/security/certificate-fetcher-direct-fetch.t.cpp
index bc134a1..183a947 100644
--- a/tests/unit/security/certificate-fetcher-direct-fetch.t.cpp
+++ b/tests/unit/security/certificate-fetcher-direct-fetch.t.cpp
@@ -216,7 +216,7 @@
 
   VALIDATE_FAILURE(this->data, "Should fail, as no interests are expected");
   BOOST_CHECK_EQUAL(this->face.sentInterests.size(), 0);
-  BOOST_CHECK(this->lastError.getCode() != ValidationError::Code::IMPLEMENTATION_ERROR);
+  BOOST_CHECK_NE(this->lastError.getCode(), ValidationError::IMPLEMENTATION_ERROR);
 }
 
 BOOST_FIXTURE_TEST_CASE(ValidateSuccessInterest, CertificateFetcherDirectFetchFixture<Cert>)
diff --git a/tests/unit/security/validation-error.t.cpp b/tests/unit/security/validation-error.t.cpp
index 6ecb94f..6c1b5f7 100644
--- a/tests/unit/security/validation-error.t.cpp
+++ b/tests/unit/security/validation-error.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2020 Regents of the University of California.
+ * Copyright (c) 2013-2022 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -34,12 +34,12 @@
 
 BOOST_AUTO_TEST_CASE(Basic)
 {
-  ValidationError e1{ValidationError::Code::INVALID_SIGNATURE};
+  ValidationError e1{ValidationError::INVALID_SIGNATURE};
   BOOST_CHECK_EQUAL(e1.getCode(), 1);
   BOOST_CHECK_EQUAL(e1.getInfo(), "");
   BOOST_CHECK_EQUAL(boost::lexical_cast<std::string>(e1), "Invalid signature");
 
-  ValidationError e2{ValidationError::Code::NO_SIGNATURE, "message"};
+  ValidationError e2{ValidationError::NO_SIGNATURE, "message"};
   BOOST_CHECK_EQUAL(e2.getCode(), 2);
   BOOST_CHECK_EQUAL(e2.getInfo(), "message");
   BOOST_CHECK_EQUAL(boost::lexical_cast<std::string>(e2), "Missing signature (message)");
diff --git a/tests/unit/security/validator-fixture.hpp b/tests/unit/security/validator-fixture.hpp
index 25cbe93..b225c53 100644
--- a/tests/unit/security/validator-fixture.hpp
+++ b/tests/unit/security/validator-fixture.hpp
@@ -68,7 +68,7 @@
   util::DummyClientFace face{m_io, {true, true}};
   std::function<void(const Interest&)> processInterest;
   CertificateCache cache{100_days};
-  ValidationError lastError{ValidationError::Code::NO_ERROR};
+  ValidationError lastError{ValidationError::NO_ERROR};
 
 private:
   const static time::milliseconds s_mockPeriod;