"deprecated" lease-time keyword for IPv6
diff --git a/src/dnsmasq.h b/src/dnsmasq.h
index 3df7940..5d2f7e2 100644
--- a/src/dnsmasq.h
+++ b/src/dnsmasq.h
@@ -655,6 +655,7 @@
 #define CONTEXT_RA_NAME       64
 #define CONTEXT_RA_STATELESS 128
 #define CONTEXT_DHCP         256
+#define CONTEXT_DEPRECATE    512
 
 struct ping_result {
   struct in_addr addr;