diff --git a/include/libtorrent/packet_pool.hpp b/include/libtorrent/packet_pool.hpp
index 21c30861f..0b23b250f 100644
--- a/include/libtorrent/packet_pool.hpp
+++ b/include/libtorrent/packet_pool.hpp
@@ -211,8 +211,8 @@ namespace libtorrent {
 			else if (allocate <= m_mtu_ceiling_slab.allocate_size) { return m_mtu_ceiling_slab.alloc(); }
 			return create_packet(allocate);
 		}
-		static int const mtu_floor_size = TORRENT_INET_MIN_MTU - TORRENT_IPV4_HEADER - TORRENT_UDP_HEADER;
-		static int const mtu_ceiling_size = TORRENT_ETHERNET_MTU - TORRENT_IPV4_HEADER - TORRENT_UDP_HEADER;
+		constexpr static int mtu_floor_size = TORRENT_INET_MIN_MTU - TORRENT_IPV4_HEADER - TORRENT_UDP_HEADER;
+		constexpr static int mtu_ceiling_size = TORRENT_ETHERNET_MTU - TORRENT_IPV4_HEADER - TORRENT_UDP_HEADER;
 		packet_slab m_syn_slab;
 		packet_slab m_mtu_floor_slab;
 		packet_slab m_mtu_ceiling_slab;
diff --git a/include/libtorrent/utp_socket_manager.hpp b/include/libtorrent/utp_socket_manager.hpp
index 0dc852d67..f4ced1852 100644
--- a/include/libtorrent/utp_socket_manager.hpp
+++ b/include/libtorrent/utp_socket_manager.hpp
@@ -133,9 +133,10 @@ namespace libtorrent {
 		void release_packet(packet_ptr p) { m_packet_pool.release(std::move(p)); }
 		void decay() { m_packet_pool.decay(); }
 
-	private:
 		// explicitly disallow assignment, to silence msvc warning
-		utp_socket_manager& operator=(utp_socket_manager const&);
+		utp_socket_manager& operator=(utp_socket_manager const&) = delete;
+
+	private:
 
 		send_fun_t m_send_fun;
 		incoming_utp_callback_t m_cb;
diff --git a/include/libtorrent/utp_stream.hpp b/include/libtorrent/utp_stream.hpp
index 5f53957f3..5cac2e20a 100644
--- a/include/libtorrent/utp_stream.hpp
+++ b/include/libtorrent/utp_stream.hpp
@@ -196,8 +196,8 @@ struct TORRENT_EXTRA_EXPORT utp_stream
 	~utp_stream();
 	utp_stream& operator=(utp_stream const&) = delete;
 	utp_stream(utp_stream const&) = delete;
-	utp_stream& operator=(utp_stream&&) noexcept = default;
-	utp_stream(utp_stream&&) noexcept = default;
+	utp_stream& operator=(utp_stream&&) noexcept = delete;
+	utp_stream(utp_stream&&) noexcept = delete;
 
 	lowest_layer_type& lowest_layer() { return *this; }
 
diff --git a/src/utp_socket_manager.cpp b/src/utp_socket_manager.cpp
index 5c8338e19..ddaab2931 100644
--- a/src/utp_socket_manager.cpp
+++ b/src/utp_socket_manager.cpp
@@ -181,8 +181,7 @@ namespace libtorrent {
 			return utp_incoming_packet(m_last_socket, p, ep, receive_time);
 		}
 
-		std::pair<socket_map_t::iterator, socket_map_t::iterator> r =
-			m_utp_sockets.equal_range(id);
+		auto r = m_utp_sockets.equal_range(id);
 
 		for (; r.first != r.second; ++r.first)
 		{
diff --git a/src/utp_stream.cpp b/src/utp_stream.cpp
index d3dee26dc..f0dacf1d3 100644
--- a/src/utp_stream.cpp
+++ b/src/utp_stream.cpp
@@ -305,14 +305,11 @@ struct utp_socket_impl
 	packet_ptr acquire_packet(int const allocate) { return m_sm.acquire_packet(allocate); }
 	void release_packet(packet_ptr p) { m_sm.release_packet(std::move(p)); }
 
-private:
-
 	// non-copyable
 	utp_socket_impl(utp_socket_impl const&) = delete;
 	utp_socket_impl const& operator=(utp_socket_impl const&) = delete;
 
 	// TODO: 2 it would be nice if not everything would have to be public here
-public:
 
 	void check_receive_buffers() const;
 
@@ -920,7 +917,7 @@ void utp_stream::on_write(void* self, std::size_t const bytes_transferred
 	}
 }
 
-void utp_stream::on_connect(void* self, error_code const& ec, bool shutdown)
+void utp_stream::on_connect(void* self, error_code const& ec, bool const shutdown)
 {
 	auto* s = static_cast<utp_stream*>(self);
 	TORRENT_ASSERT(s);
@@ -3475,7 +3472,7 @@ int utp_socket_impl::packet_timeout() const
 	return timeout;
 }
 
-void utp_socket_impl::tick(time_point now)
+void utp_socket_impl::tick(time_point const now)
 {
 	INVARIANT_CHECK;