diff --git a/blocksync/blocksync.go b/blocksync/blocksync.go
index 9ba3988cff..f02f7e5ded 100644
--- a/blocksync/blocksync.go
+++ b/blocksync/blocksync.go
@@ -199,13 +199,14 @@ func (bs *blockSyncer) ProcessBlock(ctx context.Context, peer string, blk *block
 	}
 
 	tip := bs.tipHeightHandler()
-	if !bs.buf.AddBlock(tip, newPeerBlock(peer, blk)) {
-		return nil
-	}
+	added, targetHeight := bs.buf.AddBlock(tip, newPeerBlock(peer, blk))
 	bs.mu.Lock()
 	defer bs.mu.Unlock()
-	if blk.Height() > bs.targetHeight {
-		bs.targetHeight = blk.Height()
+	if targetHeight > bs.targetHeight {
+		bs.targetHeight = targetHeight
+	}
+	if !added {
+		return nil
 	}
 	syncedHeight := tip
 	for {
diff --git a/blocksync/buffer.go b/blocksync/buffer.go
index 03c800eaff..76cba05127 100644
--- a/blocksync/buffer.go
+++ b/blocksync/buffer.go
@@ -66,18 +66,21 @@ func (b *blockBuffer) Cleanup(height uint64) {
 }
 
 // AddBlock tries to put given block into buffer and flush buffer into blockchain.
-func (b *blockBuffer) AddBlock(tipHeight uint64, blk *peerBlock) bool {
+func (b *blockBuffer) AddBlock(tipHeight uint64, blk *peerBlock) (bool, uint64) {
 	b.mu.Lock()
 	defer b.mu.Unlock()
 	blkHeight := blk.block.Height()
-	if blkHeight > tipHeight && blkHeight <= tipHeight+b.bufferSize {
-		if _, ok := b.blockQueues[blkHeight]; !ok {
-			b.blockQueues[blkHeight] = newUniQueue()
-		}
-		b.blockQueues[blkHeight].enque(blk)
-		return true
+	if blkHeight <= tipHeight {
+		return false, 0
+	}
+	if blkHeight > tipHeight+b.bufferSize {
+		return false, tipHeight + b.bufferSize
+	}
+	if _, ok := b.blockQueues[blkHeight]; !ok {
+		b.blockQueues[blkHeight] = newUniQueue()
 	}
-	return false
+	b.blockQueues[blkHeight].enque(blk)
+	return true, blkHeight
 }
 
 // GetBlocksIntervalsToSync returns groups of syncBlocksInterval are missing upto targetHeight.