diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index d36e1a8..6e98150 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -10,11 +10,12 @@ jobs:
       fail-fast: false
       matrix:
         node-version:
-          - 14
-          - 12
+          - 22
+          - 20
+          - 18
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-node@v2
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
       - run: npm install
diff --git a/index.d.ts b/index.d.ts
index 58f133a..ee8bc27 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1,4 +1,4 @@
-export interface CSPair { // eslint-disable-line @typescript-eslint/naming-convention
+export type CSPair = { // eslint-disable-line @typescript-eslint/naming-convention
 	/**
 	The ANSI terminal control sequence for starting this style.
 	*/
@@ -8,9 +8,9 @@ export interface CSPair { // eslint-disable-line @typescript-eslint/naming-conve
 	The ANSI terminal control sequence for ending this style.
 	*/
 	readonly close: string;
-}
+};
 
-export interface ColorBase {
+export type ColorBase = {
 	/**
 	The ANSI terminal control sequence for ending this color.
 	*/
@@ -21,9 +21,9 @@ export interface ColorBase {
 	ansi256(code: number): string;
 
 	ansi16m(red: number, green: number, blue: number): string;
-}
+};
 
-export interface Modifier {
+export type Modifier = {
 	/**
 	Resets the current color chain.
 	*/
@@ -70,9 +70,9 @@ export interface Modifier {
 	Puts a horizontal line through the center of the text. (Not widely supported)
 	*/
 	readonly strikethrough: CSPair;
-}
+};
 
-export interface ForegroundColor {
+export type ForegroundColor = {
 	readonly black: CSPair;
 	readonly red: CSPair;
 	readonly green: CSPair;
@@ -100,9 +100,9 @@ export interface ForegroundColor {
 	readonly cyanBright: CSPair;
 	readonly magentaBright: CSPair;
 	readonly whiteBright: CSPair;
-}
+};
 
-export interface BackgroundColor {
+export type BackgroundColor = {
 	readonly bgBlack: CSPair;
 	readonly bgRed: CSPair;
 	readonly bgGreen: CSPair;
@@ -130,9 +130,9 @@ export interface BackgroundColor {
 	readonly bgCyanBright: CSPair;
 	readonly bgMagentaBright: CSPair;
 	readonly bgWhiteBright: CSPair;
-}
+};
 
-export interface ConvertColor {
+export type ConvertColor = {
 	/**
 	Convert from the RGB color space to the ANSI 256 color space.
 
@@ -178,7 +178,7 @@ export interface ConvertColor {
 	@param hex - A hexadecimal string containing RGB data.
 	*/
 	hexToAnsi(hex: string): number;
-}
+};
 
 /**
 Basic modifier names.
diff --git a/index.js b/index.js
index d7bede4..eaa7bed 100644
--- a/index.js
+++ b/index.js
@@ -109,7 +109,7 @@ function assembleStyles() {
 	// From https://github.com/Qix-/color-convert/blob/3f0e0d4e92e235796ccb17f6e85c72094a651f49/conversions.js
 	Object.defineProperties(styles, {
 		rgbToAnsi256: {
-			value: (red, green, blue) => {
+			value(red, green, blue) {
 				// We use the extended greyscale palette here, with the exception of
 				// black and white. normal palette only has 4 greyscale shades.
 				if (red === green && green === blue) {
@@ -132,7 +132,7 @@ function assembleStyles() {
 			enumerable: false,
 		},
 		hexToRgb: {
-			value: hex => {
+			value(hex) {
 				const matches = /[a-f\d]{6}|[a-f\d]{3}/i.exec(hex.toString(16));
 				if (!matches) {
 					return [0, 0, 0];
@@ -161,7 +161,7 @@ function assembleStyles() {
 			enumerable: false,
 		},
 		ansi256ToAnsi: {
-			value: code => {
+			value(code) {
 				if (code < 8) {
 					return 30 + code;
 				}
diff --git a/index.test-d.ts b/index.test-d.ts
index 8dc8e32..1571549 100644
--- a/index.test-d.ts
+++ b/index.test-d.ts
@@ -1,5 +1,11 @@
 import {expectAssignable, expectError, expectType} from 'tsd';
-import ansiStyles, {CSPair, ModifierName, ForegroundColorName, BackgroundColorName, ColorName} from './index.js';
+import ansiStyles, {
+	type BackgroundColorName,
+	type ColorName,
+	type CSPair,
+	type ForegroundColorName,
+	type ModifierName,
+} from './index.js';
 
 expectType<ReadonlyMap<number, number>>(ansiStyles.codes);
 
diff --git a/package.json b/package.json
index 6cd3ca5..dd26fb6 100644
--- a/package.json
+++ b/package.json
@@ -46,9 +46,9 @@
 		"text"
 	],
 	"devDependencies": {
-		"ava": "^3.15.0",
+		"ava": "^6.1.3",
 		"svg-term-cli": "^2.1.1",
-		"tsd": "^0.19.0",
-		"xo": "^0.47.0"
+		"tsd": "^0.31.1",
+		"xo": "^0.58.0"
 	}
 }
diff --git a/test/test.js b/test/test.js
index 40e4875..aed48fa 100644
--- a/test/test.js
+++ b/test/test.js
@@ -1,5 +1,10 @@
 import test from 'ava';
-import ansiStyles, {modifierNames, foregroundColorNames, backgroundColorNames, colorNames} from '../index.js';
+import ansiStyles, {
+	backgroundColorNames,
+	colorNames,
+	foregroundColorNames,
+	modifierNames,
+} from '../index.js';
 
 test('return ANSI escape codes', t => {
 	t.is(ansiStyles.green.open, '\u001B[32m');