diff --git a/.changeset/friendly-numbers-rest.md b/.changeset/friendly-numbers-rest.md
new file mode 100644
index 0000000000..9bc93445fd
--- /dev/null
+++ b/.changeset/friendly-numbers-rest.md
@@ -0,0 +1,5 @@
+---
+"viem": patch
+---
+
+Fixes an issue where CIP-64 are sent as EIP-1559 transactions
diff --git a/src/chains/celo/sendTransaction.test.ts b/src/chains/celo/sendTransaction.test.ts
new file mode 100644
index 0000000000..877051403b
--- /dev/null
+++ b/src/chains/celo/sendTransaction.test.ts
@@ -0,0 +1,99 @@
+import { describe, expect, test, vi } from 'vitest'
+import { accounts } from '~test/src/constants.js'
+import { privateKeyToAccount } from '~viem/accounts/privateKeyToAccount.js'
+import {
+  type EIP1193RequestFn,
+  type PublicRpcSchema,
+  type WalletRpcSchema,
+  createTransport,
+  createWalletClient,
+} from '../../index.js'
+import { celo } from '../index.js'
+
+describe('sendTransaction()', () => {
+  // We need a local account
+  const account = privateKeyToAccount(accounts[0].privateKey)
+  const toAddress = account.address
+  const transactionHash = '0xtransaction-hash'
+  const feeCurrencyAddress = '0x0000000000000000000000000000000000000fee'
+  const transportRequestMock = vi.fn(async (request) => {
+    if (request.method === 'eth_chainId') {
+      return celo.id
+    }
+
+    if (request.method === 'eth_getBlockByNumber') {
+      // We just need baseFeePerGas for gas estimation
+      return {
+        baseFeePerGas: '0x12a05f200',
+      }
+    }
+
+    if (request.method === 'eth_maxPriorityFeePerGas') {
+      return 1n
+    }
+
+    if (request.method === 'eth_estimateGas') {
+      return 1n
+    }
+
+    if (request.method === 'eth_getTransactionCount') {
+      return 0
+    }
+
+    if (request.method === 'eth_sendRawTransaction') {
+      return transactionHash
+    }
+
+    return null
+  }) as EIP1193RequestFn<WalletRpcSchema & PublicRpcSchema>
+
+  const mockTransport = () =>
+    createTransport({
+      key: 'mock',
+      name: 'Mock Transport',
+      request: transportRequestMock,
+      type: 'mock',
+    })
+
+  const client = createWalletClient({
+    transport: mockTransport,
+    chain: celo,
+    account,
+  })
+
+  test('provides valid transaction params to sign for eth_sendRawTransaction (local account) for CIP-64', async () => {
+    const hash = await client.sendTransaction({
+      value: 1n,
+      to: toAddress,
+      feeCurrency: feeCurrencyAddress,
+      maxFeePerGas: 123n,
+      maxPriorityFeePerGas: 123n,
+    })
+
+    expect(hash).toEqual(transactionHash)
+    expect(transportRequestMock).toHaveBeenLastCalledWith({
+      method: 'eth_sendRawTransaction',
+      params: [
+        '0x7bf87782a4ec807b7b0194f39fd6e51aad88f6f4ce6ab8827279cfffb922660180c0940000000000000000000000000000000000000fee01a038c5dfc128d40b147544b13572dbb0462b9389a8a687d0fe32973e435d7de23aa03c01d6bff1279e94f53a1244302de288bd335bc3a1e61da73fd6215f6d67ccf2',
+      ],
+    })
+  })
+
+  test('provides valid transaction params to sign for eth_sendRawTransaction (local account) for CIP-42', async () => {
+    const hash = await client.sendTransaction({
+      value: 1n,
+      to: toAddress,
+      feeCurrency: feeCurrencyAddress,
+      gatewayFee: 123n,
+      gatewayFeeRecipient: '0x0000000000000000000000000000000000000001',
+    })
+
+    expect(hash).toEqual(transactionHash)
+    expect(transportRequestMock).toHaveBeenLastCalledWith({
+      method: 'eth_sendRawTransaction',
+      params: [
+        '0x7cf89282a4ec8001850165a0bc0101940000000000000000000000000000000000000fee9400000000000000000000000000000000000000017b94f39fd6e51aad88f6f4ce6ab8827279cfffb922660180c080a004389976320970e0227b20df6f79f2f35a2832d18b9732cb017d15db9f80fb44a0735b9abf965b7f38d1c659527cc93a9fc37b3a3b7bd5910d0c7db4b740be860f',
+      ],
+    })
+  })
+})
diff --git a/src/chains/celo/serializers.test.ts b/src/chains/celo/serializers.test.ts
index 26dfb2d494..e55c39c3d4 100644
--- a/src/chains/celo/serializers.test.ts
+++ b/src/chains/celo/serializers.test.ts
@@ -130,21 +130,6 @@ describe('cip42', () => {
     )
   })
 
-  test('args: gatewayFee (absent)', () => {
-    const transaction: TransactionSerializableCIP42 = {
-      ...baseCip42,
-      gatewayFeeRecipient: undefined,
-      gatewayFee: undefined,
-      type: 'cip42',
-    }
-    expect(parseTransactionCelo(serializeTransactionCelo(transaction))).toEqual(
-      {
-        ...transaction,
-        type: 'cip42',
-      },
-    )
-  })
-
   test('args: maxFeePerGas (absent)', () => {
     const transaction: TransactionSerializableCIP42 = {
       ...baseCip42,
@@ -475,6 +460,21 @@ describe('cip64', () => {
     expect(parseTransactionCelo(tx1)).toEqual(parseTransactionCelo(tx2))
     expect(parseTransactionCelo(tx1)).toEqual({ ...baseCip64, type: 'cip64' })
   })
+
+  test('CIP-42 transaction that has all CIP-64 fields and CIP-64 takes precedence', () => {
+    const transaction: TransactionSerializableCIP42 = {
+      ...baseCip42,
+      gatewayFeeRecipient: undefined,
+      gatewayFee: undefined,
+      type: 'cip42',
+    }
+    expect(parseTransactionCelo(serializeTransactionCelo(transaction))).toEqual(
+      {
+        ...transaction,
+        type: 'cip64',
+      },
+    )
+  })
 })
 
 describe('invalid params specific to CIP-42', () => {
diff --git a/src/chains/celo/serializers.ts b/src/chains/celo/serializers.ts
index 2cc385e350..7e9c7506a8 100644
--- a/src/chains/celo/serializers.ts
+++ b/src/chains/celo/serializers.ts
@@ -231,7 +231,7 @@ export function assertTransactionCIP64(
   )
     throw new TipAboveFeeCapError({ maxFeePerGas, maxPriorityFeePerGas })
 
-  if (isPresent(feeCurrency) && !feeCurrency?.startsWith('0x')) {
+  if (isPresent(feeCurrency) && !isAddress(feeCurrency)) {
     throw new BaseError(
       '`feeCurrency` MUST be a token address for CIP-64 transactions.',
     )
diff --git a/src/chains/celo/utils.test.ts b/src/chains/celo/utils.test.ts
index b32bc0cc47..858cd6bc02 100644
--- a/src/chains/celo/utils.test.ts
+++ b/src/chains/celo/utils.test.ts
@@ -74,7 +74,7 @@ describe('isPresent', () => {
 })
 
 describe('isEIP1559', () => {
-  test('it checks if a transaction is EIP-1159', () => {
+  test('it checks if a transaction is EIP-1559', () => {
     expect(isEIP1559({})).toBe(false)
 
     expect(
@@ -118,7 +118,7 @@ describe('isEIP1559', () => {
 })
 
 describe('isCIP42', () => {
-  test('it allows forcing the type even if transaction is not EIP-1159', () => {
+  test('it allows forcing the type even if transaction is not EIP-1559', () => {
     expect(
       isCIP42({
         type: 'cip42',
@@ -203,7 +203,7 @@ describe('isCIP42', () => {
 })
 
 describe('isCIP64', () => {
-  test('it allows forcing the type even if transaction is not EIP-1159', () => {
+  test('it allows forcing the type even if transaction is not EIP-1559', () => {
     expect(
       isCIP64({
         type: 'cip64',
@@ -236,6 +236,30 @@ describe('isCIP64', () => {
     ).toBe(true)
   })
 
+  test('it recognizes valid CIP-64 with "eip1559" type provided', () => {
+    expect(
+      isCIP64({
+        type: 'eip1559',
+        feeCurrency: mockAddress,
+        gatewayFeeRecipient: '0x',
+        gatewayFee: 0n,
+        maxFeePerGas: 123n,
+        maxPriorityFeePerGas: 456n,
+        from: mockAddress,
+      }),
+    ).toBe(true)
+
+    expect(
+      isCIP64({
+        type: 'eip1559',
+        feeCurrency: mockAddress,
+        maxFeePerGas: 123n,
+        maxPriorityFeePerGas: 456n,
+        from: mockAddress,
+      }),
+    ).toBe(true)
+  })
+
   test('it does not recognize valid CIP-64', () => {
     expect(isCIP64({})).toBe(false)
 
diff --git a/src/chains/celo/utils.ts b/src/chains/celo/utils.ts
index 874de53272..bd6358e811 100644
--- a/src/chains/celo/utils.ts
+++ b/src/chains/celo/utils.ts
@@ -43,7 +43,9 @@ export function isCIP42(
   transaction: CeloTransactionSerializable | CeloTransactionRequest,
 ): transaction is TransactionSerializableCIP42 {
   // Enable end-user to force the tx to be considered as a cip42
-  if (transaction.type) return transaction.type === 'cip42'
+  if (transaction.type === 'cip42') {
+    return true
+  }
 
   return (
     isEIP1559(transaction) &&
@@ -56,8 +58,19 @@ export function isCIP42(
 export function isCIP64(
   transaction: CeloTransactionSerializable | CeloTransactionRequest,
 ): transaction is TransactionSerializableCIP64 {
-  // Enable end-user to force the tx to be considered as a cip64
-  if (transaction.type) return transaction.type === 'cip64'
+  /*
+   * Enable end user to force the tx to be considered as a CIP-64.
+   *
+   * The preliminary type will be determined as "eip1559" by src/utils/transaction/getTransactionType.ts
+   * and so we need the logic below to check for the specific value instead of checking if just any
+   * transaction type is provided. If that's anything else than "cip64" then we need to reevaluate the
+   * type based on the transaction fields.
+   *
+   * Modify with caution and according to https://github.com/celo-org/celo-proposals/blob/master/CIPs/cip-0064.md
+   */
+  if (transaction.type === 'cip64') {
+    return true
+  }
 
   return (
     isEIP1559(transaction) &&