diff --git a/core/blockchain.go b/core/blockchain.go
index 1196efb6ac..18e126657c 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -1208,63 +1208,14 @@ func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain [
 			if !bc.HasHeader(block.Hash(), block.NumberU64()) {
 				return i, fmt.Errorf("containing header #%d [%x..] unknown", block.Number(), block.Hash().Bytes()[:4])
 			}
-			var (
-				start  = time.Now()
-				logged = time.Now()
-				count  int
-			)
-			// Migrate all ancient blocks. This can happen if someone upgrades from Geth
-			// 1.8.x to 1.9.x mid-fast-sync. Perhaps we can get rid of this path in the
-			// long term.
-			for {
-				// We can ignore the error here since light client won't hit this code path.
-				frozen, _ := bc.db.Ancients()
-				if frozen >= block.NumberU64() {
-					break
-				}
-				h := rawdb.ReadCanonicalHash(bc.db, frozen)
-				b := rawdb.ReadBlock(bc.db, h, frozen)
-				size += rawdb.WriteAncientBlock(bc.db, b, rawdb.ReadReceipts(bc.db, h, frozen, bc.chainConfig), rawdb.ReadTd(bc.db, h, frozen))
-				count += 1
-
-				// Always keep genesis block in active database.
-				if b.NumberU64() != 0 {
-					deleted = append(deleted, &numberHash{b.NumberU64(), b.Hash()})
+			if block.NumberU64() == 1 {
+				// Make sure to write the genesis into the freezer
+				if frozen, _ := bc.db.Ancients(); frozen == 0 {
+					h := rawdb.ReadCanonicalHash(bc.db, 0)
+					b := rawdb.ReadBlock(bc.db, h, 0)
+					size += rawdb.WriteAncientBlock(bc.db, b, rawdb.ReadReceipts(bc.db, h, 0, bc.chainConfig), rawdb.ReadTd(bc.db, h, 0))
+					log.Info("Wrote genesis to ancients")
 				}
-				if time.Since(logged) > 8*time.Second {
-					log.Info("Migrating ancient blocks", "count", count, "elapsed", common.PrettyDuration(time.Since(start)))
-					logged = time.Now()
-				}
-				// Don't collect too much in-memory, write it out every 100K blocks
-				if len(deleted) > 100000 {
-					// Sync the ancient store explicitly to ensure all data has been flushed to disk.
-					if err := bc.db.Sync(); err != nil {
-						return 0, err
-					}
-					// Wipe out canonical block data.
-					for _, nh := range deleted {
-						rawdb.DeleteBlockWithoutNumber(batch, nh.hash, nh.number)
-						rawdb.DeleteCanonicalHash(batch, nh.number)
-					}
-					if err := batch.Write(); err != nil {
-						return 0, err
-					}
-					batch.Reset()
-					// Wipe out side chain too.
-					for _, nh := range deleted {
-						for _, hash := range rawdb.ReadAllHashes(bc.db, nh.number) {
-							rawdb.DeleteBlock(batch, hash, nh.number)
-						}
-					}
-					if err := batch.Write(); err != nil {
-						return 0, err
-					}
-					batch.Reset()
-					deleted = deleted[0:]
-				}
-			}
-			if count > 0 {
-				log.Info("Migrated ancient blocks", "count", count, "elapsed", common.PrettyDuration(time.Since(start)))
 			}
 			// Flush data into ancient database.
 			size += rawdb.WriteAncientBlock(bc.db, block, receiptChain[i], bc.GetTd(block.Hash(), block.NumberU64()))