diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 5a6119b9..1d5c1e8b 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -12,8 +12,8 @@ jobs:
         node-version:
           - 18
     steps:
-      - uses: actions/checkout@v3
-      - uses: actions/setup-node@v3
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
       - run: npm install
diff --git a/package.json b/package.json
index 52a052ca..e0339d9b 100644
--- a/package.json
+++ b/package.json
@@ -17,6 +17,7 @@
 	},
 	"main": "./distribution/index.js",
 	"types": "./distribution/index.d.ts",
+	"sideEffects": false,
 	"engines": {
 		"node": ">=18"
 	},
diff --git a/source/core/Ky.ts b/source/core/Ky.ts
index 0e8692e8..bef52b79 100644
--- a/source/core/Ky.ts
+++ b/source/core/Ky.ts
@@ -23,7 +23,7 @@ export class Ky {
 	static create(input: Input, options: Options): ResponsePromise {
 		const ky = new Ky(input, options);
 
-		const fn = async (): Promise<Response> => {
+		const function_ = async (): Promise<Response> => {
 			if (typeof ky._options.timeout === 'number' && ky._options.timeout > maxSafeTimeout) {
 				throw new RangeError(`The \`timeout\` option cannot be greater than ${maxSafeTimeout}`);
 			}
@@ -76,7 +76,7 @@ export class Ky {
 		};
 
 		const isRetriableMethod = ky._options.retry.methods.includes(ky.request.method.toLowerCase());
-		const result = (isRetriableMethod ? ky._retry(fn) : fn()) as ResponsePromise;
+		const result = (isRetriableMethod ? ky._retry(function_) : function_()) as ResponsePromise;
 
 		for (const [type, mimeType] of Object.entries(responseTypes) as ObjectEntries<typeof responseTypes>) {
 			result[type] = async () => {
@@ -250,9 +250,9 @@ export class Ky {
 		return response;
 	}
 
-	protected async _retry<T extends (...args: any) => Promise<any>>(fn: T): Promise<ReturnType<T> | void> {
+	protected async _retry<T extends (...arguments_: any) => Promise<any>>(function_: T): Promise<ReturnType<T> | void> {
 		try {
-			return await fn();
+			return await function_();
 		} catch (error) {
 			const ms = Math.min(this._calculateRetryDelay(error), maxSafeTimeout);
 			if (ms !== 0 && this._retryCount > 0) {
@@ -273,7 +273,7 @@ export class Ky {
 					}
 				}
 
-				return this._retry(fn);
+				return this._retry(function_);
 			}
 
 			throw error;
diff --git a/test/helpers/with-page.ts b/test/helpers/with-page.ts
index 7925c84b..0b72e2ff 100644
--- a/test/helpers/with-page.ts
+++ b/test/helpers/with-page.ts
@@ -1,8 +1,7 @@
-/* eslint-disable ava/no-ignored-test-files */
+
 import process from 'node:process';
-import test from 'ava';
+import test, {type ExecutionContext} from 'ava';
 import {chromium, firefox, webkit, type BrowserType, type Page} from 'playwright';
-import type {ExecutionContext} from 'ava';
 
 type Run = (t: ExecutionContext, page: Page) => Promise<void>;
 
diff --git a/test/helpers/with-performance-observer.ts b/test/helpers/with-performance-observer.ts
index 6d28ebfa..c6c9e29c 100644
--- a/test/helpers/with-performance-observer.ts
+++ b/test/helpers/with-performance-observer.ts
@@ -2,7 +2,7 @@ import {performance, PerformanceObserver} from 'node:perf_hooks';
 import process from 'node:process';
 import type {ExecutionContext} from 'ava';
 
-type Arg = {
+type Argument = {
 	name: string;
 	expectedDuration: number;
 	t: ExecutionContext;
@@ -17,7 +17,7 @@ export async function withPerformanceObserver({
 	expectedDuration,
 	t,
 	test,
-}: Arg) {
+}: Argument) {
 	// Register observer that asserts on duration when a measurement is performed
 	const obs = new PerformanceObserver(items => {
 		const measurements = items.getEntries();