diff --git a/.waf-tools/unix-socket.py b/.waf-tools/unix-socket.py
index 07d1e9e..4c98f1a 100644
--- a/.waf-tools/unix-socket.py
+++ b/.waf-tools/unix-socket.py
@@ -1,13 +1,13 @@
 # -*- Mode: python; py-indent-offset: 4; indent-tabs-mode: nil; coding: utf-8; -*-
 #
-# Copyright (c) 2014-2018, Regents of the University of California
+# Copyright (c) 2014-2019, Regents of the University of California
 #
 # GPL 3.0 license, see the COPYING.md file for more information
 
 from waflib import Options
 
 BOOST_ASIO_HAS_LOCAL_SOCKETS_CHECK = '''
-#include <boost/asio.hpp>
+#include <boost/asio/local/basic_endpoint.hpp>
 #ifndef BOOST_ASIO_HAS_LOCAL_SOCKETS
 #error "Unix sockets are not available on this platform"
 #endif
@@ -25,6 +25,5 @@
                               fragment=BOOST_ASIO_HAS_LOCAL_SOCKETS_CHECK,
                               features='cxx', use='BOOST', mandatory=False)
 
-    if conf.options.force_unix_socket or boost_asio_has_local_sockets():
-        conf.define('HAVE_UNIX_SOCKETS', 1)
-        conf.env.HAVE_UNIX_SOCKETS = True
+    conf.env.HAVE_UNIX_SOCKETS = conf.options.force_unix_socket or boost_asio_has_local_sockets()
+    conf.define_cond('HAVE_UNIX_SOCKETS', conf.env.HAVE_UNIX_SOCKETS)