diff --git a/proto/ospf/topology.c b/proto/ospf/topology.c
index 8203e4c..604c8ea 100644
--- a/proto/ospf/topology.c
+++ b/proto/ospf/topology.c
@@ -150,7 +150,7 @@ get_seqnum(struct top_hash_entry *en)
     return LSA_INITSEQNO;
   }
 
-  return en->lsa.sn++;
+  return en->lsa.sn + 1;
 }