diff --git a/src/consts.ts b/src/consts.ts
new file mode 100644
index 0000000..7657716
--- /dev/null
+++ b/src/consts.ts
@@ -0,0 +1,7 @@
+export const Y_PARITY_EIP_2098 = 27;
+export const EIP155_NUMBER = 35;
+// NOTE: Black magic number, unsure where it comes from
+export const EIGHT = 8;
+
+// NOTE: Logic stolen from https://github.com/celo-org/celo-monorepo/blob/e7ebc92cb0715dc56c9d7f613dca81e076541cf3/packages/sdk/connect/src/connection.ts#L382-L396
+export const GAS_INFLATION_FACTOR = 1.3;
diff --git a/src/lib/CeloProvider.ts b/src/lib/CeloProvider.ts
index 6dda604..cd9fbde 100644
--- a/src/lib/CeloProvider.ts
+++ b/src/lib/CeloProvider.ts
@@ -65,8 +65,7 @@ export class CeloProvider extends providers.JsonRpcProvider {
       ] as const;
 
       const tx = {
-        // @ts-expect-error
-        ...this.constructor.hexlifyTransaction(
+        ...providers.JsonRpcProvider.hexlifyTransaction(
           params.transaction,
           extraneous_keys.reduce((acc, [key]) => {
             acc[key] = true;
diff --git a/src/lib/CeloWallet.ts b/src/lib/CeloWallet.ts
index 5ebcf04..3b632db 100644
--- a/src/lib/CeloWallet.ts
+++ b/src/lib/CeloWallet.ts
@@ -122,11 +122,10 @@ export class CeloWallet extends Wallet {
    * https://github.com/ethers-io/ethers.js/blob/master/packages/abstract-signer/src.ts/index.ts
    */
   async estimateGas(
-    transaction: utils.Deferrable<CeloTransaction>
+    transaction: utils.Deferrable<CeloTransactionRequest>
   ): Promise<BigNumber> {
     this._checkProvider("estimateGas");
-    // @ts-expect-error
-    const tx: CeloTransaction = await utils.resolveProperties(transaction);
+    const tx = await utils.resolveProperties(transaction);
     return this.provider.estimateGas(tx).then(adjustForGasInflation);
   }
 
diff --git a/src/lib/transaction/utils.ts b/src/lib/transaction/utils.ts
index d0f8478..7b9d9b9 100644
--- a/src/lib/transaction/utils.ts
+++ b/src/lib/transaction/utils.ts
@@ -1,5 +1,6 @@
 import { BigNumber, BigNumberish } from "ethers";
 import { hexlify } from "ethers/lib/utils";
+import { GAS_INFLATION_FACTOR } from "../../consts";
 
 function isEmpty(value: string | BigNumberish | undefined | null) {
   return (
@@ -11,6 +12,7 @@ function isEmpty(value: string | BigNumberish | undefined | null) {
       : hexlify(value) === "0x0")
   );
 }
+
 function isPresent(value: string | BigNumberish | undefined | null) {
   return !isEmpty(value);
 }
@@ -27,6 +29,7 @@ export function isCIP64(tx: any) {
     !isPresent(tx.gatewayFeeRecipient)
   );
 }
+
 export function isCIP42(tx: any): boolean {
   return (
     isEIP1559(tx) &&
@@ -55,9 +58,6 @@ export function omit<T extends Object, K extends (keyof T)[]>(
 }
 
 export function adjustForGasInflation(gas: BigNumber): BigNumber {
-  // NOTE: Don't ask me
-  const GAS_INFLATION_FACTOR = 1.3;
-
   // NOTE: prevent floating point math
   return gas.mul(Math.floor(GAS_INFLATION_FACTOR * 100)).div(100);
 }
diff --git a/src/lib/transactions.ts b/src/lib/transactions.ts
index 90706ad..b22b0b7 100644
--- a/src/lib/transactions.ts
+++ b/src/lib/transactions.ts
@@ -9,10 +9,7 @@ import {
 } from "ethers";
 import { concatHex, isCIP64, isEIP1559, omit } from "./transaction/utils";
 import { accessListify, AccessListish } from "ethers/lib/utils";
-
-// NOTE: Black magic
-const Y_PARITY_EIP_2098 = 27;
-const BULLSHIT_NUMBER = 8;
+import { EIGHT, EIP155_NUMBER, Y_PARITY_EIP_2098 } from "../consts";
 
 // From https://github.com/ethers-io/ethers.js/blob/master/packages/bytes/src.ts/index.ts#L33
 // Copied because it doesn't seem to be exported from 'ethers' anywhere
@@ -290,7 +287,7 @@ export function serializeCeloTransaction(
     signature.v > 28
   ) {
     // No chainId provided, but the signature is signing with EIP-155; derive chainId
-    chainId = Math.floor((signature.v - 35) / 2);
+    chainId = Math.floor((signature.v - EIP155_NUMBER) / 2);
   }
 
   // We have an EIP-155 transaction (chainId was specified and non-zero)
@@ -323,7 +320,7 @@ export function serializeCeloTransaction(
     v = Y_PARITY_EIP_2098 + sig.recoveryParam;
 
     if (chainId !== 0) {
-      v += chainId * 2 + BULLSHIT_NUMBER;
+      v += chainId * 2 + EIGHT;
 
       // If an EIP-155 v (directly or indirectly; maybe _vs) was provided, check it!
       if (sig.v > Y_PARITY_EIP_2098 + 1 && sig.v !== v) {
@@ -430,9 +427,9 @@ export function parseCeloTransaction(
     let recoveryParam = tx.v;
     if (!type) {
       // celo-legacy
-      tx.chainId = Math.max(0, Math.floor((tx.v - 35) / 2));
+      tx.chainId = Math.max(0, Math.floor((tx.v - EIP155_NUMBER) / 2));
       recoveryParam = tx.v - Y_PARITY_EIP_2098;
-      recoveryParam -= tx.chainId * 2 + BULLSHIT_NUMBER;
+      recoveryParam -= tx.chainId * 2 + EIGHT;
     }
 
     // NOTE: Serialization needs to happen here because chainId may not populated before