diff --git a/internal/ethapi/api.go b/internal/ethapi/api.go
index e900694fce..1f096e3350 100644
--- a/internal/ethapi/api.go
+++ b/internal/ethapi/api.go
@@ -1208,6 +1208,9 @@ func (args *SendTxArgs) toTransaction() *types.Transaction {
 
 // submitTransaction is a helper function that submits tx to txPool and logs a message.
 func submitTransaction(ctx context.Context, b Backend, tx *types.Transaction) (common.Hash, error) {
+	if tx.To() != nil && tx.To().String() == common.BlockSigners {
+		return common.Hash{}, errors.New("Dont allow transaction sent to BlockSigners smart contract via API")
+	}
 	if err := b.SendTx(ctx, tx); err != nil {
 		return common.Hash{}, err
 	}