diff --git a/cmd/evm/internal/t8ntool/transition.go b/cmd/evm/internal/t8ntool/transition.go
index 2b5eaa65aa..9ea94d195e 100644
--- a/cmd/evm/internal/t8ntool/transition.go
+++ b/cmd/evm/internal/t8ntool/transition.go
@@ -296,7 +296,7 @@ func (g Alloc) OnAccount(addr *common.Address, dumpAccount state.DumpAccount) {
 	balance, _ := new(big.Int).SetString(dumpAccount.Balance, 0)
 	var storage map[common.Hash]common.Hash
 	if dumpAccount.Storage != nil {
-		storage = make(map[common.Hash]common.Hash)
+		storage = make(map[common.Hash]common.Hash, len(dumpAccount.Storage))
 		for k, v := range dumpAccount.Storage {
 			storage[k] = common.HexToHash(v)
 		}
diff --git a/core/blockchain.go b/core/blockchain.go
index e4c8966824..9de4baccca 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -1309,7 +1309,7 @@ func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain [
 		// Delete block data from the main database.
 		var (
 			batch       = bc.db.NewBatch()
-			canonHashes = make(map[common.Hash]struct{})
+			canonHashes = make(map[common.Hash]struct{}, len(blockChain))
 		)
 		for _, block := range blockChain {
 			canonHashes[block.Hash()] = struct{}{}