diff --git a/tests/unit/util/io.t.cpp b/tests/unit/util/io.t.cpp
index 8b19fe3..ebe5799 100644
--- a/tests/unit/util/io.t.cpp
+++ b/tests/unit/util/io.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2021 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).
  *
@@ -67,7 +67,7 @@
 {
   T t;
   std::ostringstream os(std::ios_base::binary);
-  io::saveBuffer(t.blob.data(), t.blob.size(), os, t.encoding);
+  io::saveBuffer(t.blob, os, t.encoding);
   BOOST_CHECK_EQUAL(os.str(), t.stream.str());
 }
 
@@ -86,7 +86,7 @@
   NullStreambuf nullbuf;
   std::ostream out(&nullbuf);
   const Buffer buffer(1);
-  BOOST_CHECK_THROW(io::saveBuffer(buffer.data(), buffer.size(), out, io::NO_ENCODING), io::Error);
+  BOOST_CHECK_THROW(io::saveBuffer(buffer, out, io::NO_ENCODING), io::Error);
 }
 
 BOOST_AUTO_TEST_CASE(UnknownIoEncoding)
@@ -94,7 +94,7 @@
   std::stringstream ss;
   BOOST_CHECK_THROW(io::loadTlv<Name>(ss, static_cast<io::IoEncoding>(5)), std::invalid_argument);
   BOOST_CHECK_THROW(io::loadBuffer(ss, static_cast<io::IoEncoding>(5)), std::invalid_argument);
-  BOOST_CHECK_THROW(io::saveBuffer(nullptr, 0, ss, static_cast<io::IoEncoding>(5)), std::invalid_argument);
+  BOOST_CHECK_THROW(io::saveBuffer({}, ss, static_cast<io::IoEncoding>(5)), std::invalid_argument);
 }
 
 class FileIoFixture
diff --git a/tests/unit/util/sha256.t.cpp b/tests/unit/util/sha256.t.cpp
index 501a015..3340204 100644
--- a/tests/unit/util/sha256.t.cpp
+++ b/tests/unit/util/sha256.t.cpp
@@ -134,7 +134,7 @@
   auto expected = fromHex("b372edfd4d6a4db2cfeaeead6c34fdee9b9e759f7b8d799cf8067e39e7f2886c");
 
   Sha256 statefulSha256;
-  statefulSha256 << Block{input, sizeof(input)};
+  statefulSha256 << Block{input};
   ConstBufferPtr digest = statefulSha256.computeDigest();
 
   BOOST_CHECK_EQUAL(statefulSha256.empty(), false);
diff --git a/tests/unit/util/simple-notification.hpp b/tests/unit/util/simple-notification.hpp
index 280045a..acfa172 100644
--- a/tests/unit/util/simple-notification.hpp
+++ b/tests/unit/util/simple-notification.hpp
@@ -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,
@@ -28,7 +28,7 @@
 #ifndef NDN_CXX_TESTS_UNIT_UTIL_SIMPLE_NOTIFICATION_HPP
 #define NDN_CXX_TESTS_UNIT_UTIL_SIMPLE_NOTIFICATION_HPP
 
-#include "ndn-cxx/encoding/encoding-buffer.hpp"
+#include "ndn-cxx/encoding/block-helpers.hpp"
 
 namespace ndn {
 namespace util {
@@ -53,11 +53,7 @@
   Block
   wireEncode() const
   {
-    ndn::EncodingBuffer buffer;
-    buffer.prependByteArrayBlock(0x8888,
-                                 reinterpret_cast<const uint8_t*>(m_message.c_str()),
-                                 m_message.size());
-    return buffer.block();
+    return makeStringBlock(0x8888, m_message);
   }
 
   void