diff --git a/core/block_validator.go b/core/block_validator.go
index 2afe81ce0b..6f2c40b2ec 100644
--- a/core/block_validator.go
+++ b/core/block_validator.go
@@ -79,6 +79,12 @@ func (v *BlockValidator) ValidateBody(block *types.Block) error {
 	}
 
 	validateFuns := []func() error{
+		func() error {
+			if v.bc.HasBlockAndState(block.Hash(), block.NumberU64()) {
+				return ErrKnownBlock
+			}
+			return nil
+		},
 		func() error {
 			if hash := types.DeriveSha(block.Transactions(), trie.NewStackTrie(nil)); hash != header.TxHash {
 				return fmt.Errorf("transaction root hash mismatch: have %x, want %x", hash, header.TxHash)