--- config.h.in.orig	2018-04-14 15:52:32 UTC
+++ config.h.in
@@ -18,6 +18,10 @@
 /* Indicator that RELP is present */
 #undef ENABLE_RELP
 
+/* Indicator that syslog(3) sends RFC5424 format via the local unix
+   socket, rather than the traditional RFC3164 */
+#undef ENABLE_IMUXSOCK_RFC5424
+
 /* Regular expressions support enabled. */
 #undef FEATURE_REGEXP