diff --git a/internal/ethapi/api.go b/internal/ethapi/api.go
index 670b6800b6..1fd916d903 100644
--- a/internal/ethapi/api.go
+++ b/internal/ethapi/api.go
@@ -1623,6 +1623,8 @@ func newRPCTransaction(tx *types.Transaction, blockHash common.Hash, blockNumber
 		result.MaxSubmissionFee = (*hexutil.Big)(inner.MaxSubmissionFee)
 		result.GasFeeCap = (*hexutil.Big)(inner.GasFeeCap)
 		result.ChainID = (*hexutil.Big)(inner.ChainId)
+	case *types.ArbitrumUnsignedTx:
+		result.ChainID = (*hexutil.Big)(inner.ChainId)
 	}
 	return result
 }