diff -Nur a/include/libtorrent/aux_/socket_type.hpp b/include/libtorrent/aux_/socket_type.hpp
--- a/include/libtorrent/aux_/socket_type.hpp	2019-09-24 00:28:43.000000000 +0100
+++ b/include/libtorrent/aux_/socket_type.hpp	2019-12-17 22:48:27.679305842 +0000
@@ -184,6 +184,10 @@
 		using receive_buffer_size = tcp::socket::receive_buffer_size;
 		using send_buffer_size = tcp::socket::send_buffer_size;
 
+#if BOOST_VERSION >= 106600
+		using executor_type = tcp::socket::executor_type;
+#endif
+
 		explicit socket_type(io_service& ios): m_io_service(ios), m_type(0) {}
 		~socket_type();