diff --git a/mdns-repeater.c b/mdns-repeater.c
index fec62da..fc35010 100644
--- a/mdns-repeater.c
+++ b/mdns-repeater.c
@@ -46,6 +46,10 @@
 #define MAX_SOCKS 16
 #define MAX_SUBNETS 16
 
+#ifndef HGVERSION
+#define HGVERSION "unknown"
+#endif
+
 struct if_sock {
 	const char *ifname;	/* interface name  */
 	int sockfd;		/* socket filedesc */