--- a/libupnpp/config.h.in
+++ b/libupnpp/config.h.in
@@ -36,6 +36,9 @@
 /* Define to 1 if you have the <stdlib.h> header file. */
 #undef HAVE_STDLIB_H
 
+/* Define to 1 if you have the `std::future`. */
+#undef HAVE_STD_FUTURE
+
 /* Define to 1 if you have the <strings.h> header file. */
 #undef HAVE_STRINGS_H
 
@@ -54,7 +57,8 @@
 /* Define to 1 if you have the `UpnpSetLogLevel' function. */
 #undef HAVE_UPNPSETLOGLEVEL
 
-/* Define to the sub-directory where libtool stores uninstalled libraries. */
+/* Define to the sub-directory in which libtool stores uninstalled libraries.
+   */
 #undef LT_OBJDIR
 
 /* Define to the address where bug reports for this package should be sent. */