diff --git a/php_v8js_macros.h b/php_v8js_macros.h
index 5a9c18a..a17fe8b 100644
--- a/php_v8js_macros.h
+++ b/php_v8js_macros.h
@@ -2,12 +2,13 @@
   +----------------------------------------------------------------------+
   | PHP Version 5                                                        |
   +----------------------------------------------------------------------+
-  | Copyright (c) 1997-2013 The PHP Group                                |
+  | Copyright (c) 1997-2016 The PHP Group                                |
   +----------------------------------------------------------------------+
   | http://www.opensource.org/licenses/mit-license.php  MIT License      |
   +----------------------------------------------------------------------+
   | Author: Jani Taskinen <jani.taskinen@iki.fi>                         |
   | Author: Patrick Reilly <preilly@php.net>                             |
+  | Author: Stefan Siegl <stesie@php.net>                                |
   +----------------------------------------------------------------------+
 */
 
@@ -27,6 +28,13 @@
 #include <vector>
 #include <mutex>
 
+#include <cmath>
+#ifndef isnan
+/* php.h requires the isnan() macro, which is removed by c++ <cmath> header,
+ * work around: re-define the macro to std::isnan function */
+#define isnan(a) std::isnan(a)
+#endif
+
 extern "C" {
 #include "php.h"
 #include "php_v8js.h"