diff --git a/sys/netinet6/in6.h b/sys/netinet6/in6.h
--- a/sys/netinet6/in6.h
+++ b/sys/netinet6/in6.h
@@ -358,11 +358,11 @@
 
 #define IFA6_IS_DEPRECATED(a) \
 	((a)->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME && \
-	 (u_int32_t)((time_uptime - (a)->ia6_updatetime)) > \
+	 (u_int32_t)((time_uptime - (a)->ia6_updatetime)) >= \
 	 (a)->ia6_lifetime.ia6t_pltime)
 #define IFA6_IS_INVALID(a) \
 	((a)->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME && \
-	 (u_int32_t)((time_uptime - (a)->ia6_updatetime)) > \
+	 (u_int32_t)((time_uptime - (a)->ia6_updatetime)) >= \
 	 (a)->ia6_lifetime.ia6t_vltime)
 #endif /* _KERNEL */