diff --git a/web3.js/src/connection.js b/web3.js/src/connection.js
index 0d683be13e..14b3aba629 100644
--- a/web3.js/src/connection.js
+++ b/web3.js/src/connection.js
@@ -431,8 +431,15 @@ export class Connection {
   async sendRawTransaction(
     rawTransaction: Buffer,
   ): Promise<TransactionSignature> {
+
+    // sendTransaction RPC API requires a u64 length field prepended to the raw
+    // Transaction bytes
+    const rpcTransaction = Buffer.alloc(8 + rawTransaction.length);
+    rpcTransaction.writeUInt32LE(rawTransaction.length, 0);
+    rawTransaction.copy(rpcTransaction, 8);
+
     const unsafeRes = await this._rpcRequest('sendTransaction', [
-      [...rawTransaction],
+      [...rpcTransaction],
     ]);
     const res = SendTransactionRpcResult(unsafeRes);
     if (res.error) {
diff --git a/web3.js/src/transaction.js b/web3.js/src/transaction.js
index e48f6a7124..e0ad14fe6d 100644
--- a/web3.js/src/transaction.js
+++ b/web3.js/src/transaction.js
@@ -365,21 +365,20 @@ export class Transaction {
     shortvec.encodeLength(signatureCount, signatures.length);
     const transactionLength =
       signatureCount.length + signatures.length * 64 + signData.length;
-    const wireTransaction = Buffer.alloc(8 + transactionLength);
-    wireTransaction.writeUInt32LE(transactionLength, 0);
+    const wireTransaction = Buffer.alloc(transactionLength);
     invariant(signatures.length < 256);
-    Buffer.from(signatureCount).copy(wireTransaction, 8);
+    Buffer.from(signatureCount).copy(wireTransaction, 0);
     signatures.forEach(({signature}, index) => {
       invariant(signature !== null, `null signature`);
       invariant(signature.length === 64, `signature has invalid length`);
       Buffer.from(signature).copy(
         wireTransaction,
-        8 + signatureCount.length + index * 64,
+        signatureCount.length + index * 64,
       );
     });
     signData.copy(
       wireTransaction,
-      8 + signatureCount.length + signatures.length * 64,
+      signatureCount.length + signatures.length * 64,
     );
     invariant(
       wireTransaction.length <= PACKET_DATA_SIZE,
@@ -427,11 +426,6 @@ export class Transaction {
     // Slice up wire data
     let byteArray = [...buffer];
 
-    const transactionLength = byteArray.slice(0, 8);
-    byteArray = byteArray.slice(8);
-    const len = Buffer.from(transactionLength).readIntLE(0, 4);
-    invariant(len == byteArray.length);
-
     const signatureCount = shortvec.decodeLength(byteArray);
     let signatures = [];
     for (let i = 0; i < signatureCount; i++) {
diff --git a/web3.js/test/transaction.test.js b/web3.js/test/transaction.test.js
index b13b39296f..8c29f62954 100644
--- a/web3.js/test/transaction.test.js
+++ b/web3.js/test/transaction.test.js
@@ -51,14 +51,6 @@ test('parse wire format and serialize', () => {
   expectedTransaction.sign(sender);
 
   const wireTransaction = Buffer.from([
-    221,
-    0,
-    0,
-    0,
-    0,
-    0,
-    0,
-    0,
     1,
     50,
     238,