diff --git a/src/part_file.cpp b/src/part_file.cpp
index 865ff1f31..55044f9c0 100644
--- a/src/part_file.cpp
+++ b/src/part_file.cpp
@@ -262,7 +262,7 @@ namespace libtorrent {
 
 		// we're only supposed to move part files from a fence job. i.e. no other
 		// disk jobs are supposed to be in-flight at this point
-		TORRENT_ASSERT(!m_file || m_file.unique());
+		TORRENT_ASSERT(!m_file || m_file.use_count() == 1);
 		m_file.reset();
 
 		if (!m_piece_map.empty())
diff --git a/src/session.cpp b/src/session.cpp
index 247826ec2..fb84b251c 100644
--- a/src/session.cpp
+++ b/src/session.cpp
@@ -393,7 +393,7 @@ namespace {
 		// to keep the session_impl alive
 		m_impl->call_abort();
 
-		if (m_thread && m_thread.unique())
+		if (m_thread && m_thread.use_count() == 1)
 		{
 #if defined TORRENT_ASIO_DEBUGGING
 			wait_for_asio_handlers();
@@ -424,7 +424,7 @@ namespace {
 	session_proxy& session_proxy::operator=(session_proxy&&) noexcept = default;
 	session_proxy::~session_proxy()
 	{
-		if (m_thread && m_thread.unique())
+		if (m_thread && m_thread.use_count() == 1)
 		{
 #if defined TORRENT_ASIO_DEBUGGING
 			wait_for_asio_handlers();
diff --git a/src/session_impl.cpp b/src/session_impl.cpp
index 3746e13f7..1abcdbdb2 100644
--- a/src/session_impl.cpp
+++ b/src/session_impl.cpp
@@ -3153,7 +3153,7 @@ namespace aux {
 		if (!m_undead_peers.empty())
 		{
 			auto const remove_it = std::remove_if(m_undead_peers.begin(), m_undead_peers.end()
-				, std::bind(&std::shared_ptr<peer_connection>::unique, _1));
+				, [](std::shared_ptr<peer_connection>& ptr) { return ptr.use_count() == 1; });
 			m_undead_peers.erase(remove_it, m_undead_peers.end());
 			if (m_undead_peers.empty())
 			{