diff --git a/chotki.go b/chotki.go
index 5ca8656..0746146 100644
--- a/chotki.go
+++ b/chotki.go
@@ -496,15 +496,12 @@ func (cho *Chotki) Broadcast(ctx context.Context, records protocol.Records, exce
 // Here new packets are timestamped and queued for save
 func (cho *Chotki) CommitPacket(ctx context.Context, lit byte, ref rdx.ID, body protocol.Records) (id rdx.ID, err error) {
 	cho.lock.Lock()
+	defer cho.lock.Unlock()
 
 	if cho.db == nil {
-		cho.lock.Unlock()
 		return rdx.BadId, ErrClosed
 	}
-
 	id = (cho.last & ^rdx.OffMask) + rdx.ProInc
-	cho.last = id
-	cho.lock.Unlock()
 	i := protocol.Record('I', id.ZipBytes())
 	r := protocol.Record('R', ref.ZipBytes())
 	packet := protocol.Record(lit, i, r, protocol.Join(body...))
@@ -566,6 +563,13 @@ func (cho *Chotki) drain(ctx context.Context, recs protocol.Records) (err error)
 			return parseErr
 		}
 
+		if id.Src() == cho.src && id > cho.last {
+			if id.Off() != 0 {
+				return rdx.ErrBadPacket
+			}
+			cho.last = id
+		}
+
 		pb, noApply := pebble.Batch{}, false
 
 		cho.log.DebugCtx(ctx, "new packet", "type", string(lit), "packet", id.String())