diff --git a/include/simulator/config.hpp b/include/simulator/config.hpp
index 9f751b0..325af33 100644
--- a/include/simulator/config.hpp
+++ b/include/simulator/config.hpp
@@ -37,6 +37,14 @@ All rights reserved.
 #define LIBSIMULATOR_USE_MOVE 0
 #endif
 
+#if defined __clang__ || defined __GNUC__
+#define LIBSIMULATOR_NO_RETURN __attribute((noreturn))
+#elif _MSC_VER
+#define LIBSIMULATOR_NO_RETURN __declspec(noreturn)
+#else
+#define LIBSIMULATOR_NO_RETURN
+#endif
+
 #ifdef _MSC_VER
 #pragma warning(push)
 // warning C4251: X: class Y needs to have dll-interface to be used by clients of struct
diff --git a/include/simulator/simulator.hpp b/include/simulator/simulator.hpp
index 4d9793f..6fbaa2c 100644
--- a/include/simulator/simulator.hpp
+++ b/include/simulator/simulator.hpp
@@ -325,8 +325,8 @@ namespace sim
 			return lhs_end == rhs_end;
 		}
 
-		value_type operator*() const { return m_results[m_idx]; }
-		value_type const* operator->() const { return &m_results[m_idx]; }
+		value_type operator*() const { assert(m_idx >= 0); return m_results[static_cast<std::size_t>(m_idx)]; }
+		value_type const* operator->() const { assert(m_idx >= 0); return &m_results[static_cast<std::size_t>(m_idx)]; }
 
 		basic_resolver_iterator& operator++() { ++m_idx; return *this; }
 		basic_resolver_iterator operator++(int)
@@ -731,9 +731,9 @@ namespace sim
 				async_write_some_impl(b, handler);
 			}
 
-			void async_write_some(null_buffers const&
+			void LIBSIMULATOR_NO_RETURN async_write_some(null_buffers const&
 				, std::function<void(boost::system::error_code const&
-					, std::size_t)> const& /* handler */)
+				, std::size_t)> const& /* handler */)
 			{
 				if (m_send_handler) abort_send_handler();
 				assert(false && "not supported yet");
diff --git a/src/socks_server.cpp b/src/socks_server.cpp
index e6bb5f5..6f68cec 100644
--- a/src/socks_server.cpp
+++ b/src/socks_server.cpp
@@ -282,7 +282,9 @@ namespace sim
 		}
 
 		std::printf("socks_connection: received %s request address type: %d\n"
-			, command == 1 ? "CONNECT" : "BIND", atyp);
+			, command == 1 ? "CONNECT"
+			: command == 2 ? "BIND"
+			: "UDP_ASSOCIATE", atyp);
 
 		switch (atyp)
 		{