diff --git a/.eslintrc b/.eslintrc
new file mode 100644
index 0000000..bb612a0
--- /dev/null
+++ b/.eslintrc
@@ -0,0 +1,27 @@
+{
+	"root": true,
+	"extends": "@ljharb",
+	"parserOptions": {
+		"ecmaVersion": "2018"
+	},
+	"env": {
+		"es6": true
+	},
+	"rules": {
+		"consistent-return": 1,
+		"dot-notation": [2, { "allowKeywords": true }],
+		"func-name-matching": 0,
+		"max-nested-callbacks": 0,
+		"max-params": [2, 4],
+		"no-console": 0,
+		"sort-keys": 0,
+	},
+	"overrides": [
+		{
+			"files": "test*",
+			"rules": {
+				"max-nested-callbacks": 0,
+			},
+		},
+	],
+}
diff --git a/bin.js b/bin.js
index 812c995..5abf018 100755
--- a/bin.js
+++ b/bin.js
@@ -13,27 +13,33 @@ const { filename } = finder(process.cwd()).next();
 
 const getLockfile = require('./getLockfile');
 
-const { argv: { output, date, package: pkg } } = require('yargs')
+const {
+	argv: {
+		output,
+		date,
+		'package': pkg
+	}
+} = require('yargs')
 	.help()
 	.option('date', {
 		type: 'string',
 		describe: '“now”, or a date (same format as `new Date()`)',
 		demandOption: true,
-		coerce(arg) { return arg === 'now' ? arg : new Date(arg); },
+		coerce: function (arg) { return arg === 'now' ? arg : new Date(arg); }
 	})
 	.option('package', {
 		type: 'string',
 		describe: 'path to a `package.json` file',
 		normalize: true,
-		coerce(arg) { return path.resolve(arg); },
+		coerce: function (arg) { return path.resolve(arg); }
 	})
 	.default('package', filename, path.relative(process.cwd(), filename))
 	.option('output', {
 		alias: 'o',
 		describe: 'output file path',
 		normalize: true,
-		demandOption: true,
-	})
+		demandOption: true
+	});
 
 getLockfile(pkg, date === 'now' ? undefined : date, console.log.bind(console))
 	.then(lockfile => writeFile(output, lockfile))
diff --git a/getLockfile.js b/getLockfile.js
index c8ce708..c8cbb9b 100644
--- a/getLockfile.js
+++ b/getLockfile.js
@@ -28,11 +28,14 @@ module.exports = function getLockfile(packageFile, date, logger = () => {}) {
 	return Promise.all([tmpDirP, copyPkg]).then(([tmpDir]) => new Promise((resolve, reject) => {
 		const PATH = path.join(tmpDir, '../node_modules/.bin');
 		logger(chalk.blue(`Running npm install to create lockfile for ${dateStr}...`));
-		exec(`PATH=${PATH}:\$PATH npm install --package-lock-only --before=${dateStr}`, { cwd: tmpDir }, (err) => {
-			if (err) { reject(err); }
-			else { resolve(tmpDir); }
+		exec(`PATH=${PATH}:$PATH npm install --package-lock-only --before=${dateStr}`, { cwd: tmpDir }, err => {
+			if (err) {
+				reject(err);
+			} else {
+				resolve(tmpDir);
+			}
 		});
-	})).then((tmpDir) => {
+	})).then(tmpDir => {
 		logger(chalk.blue(`Reading lockfile contents for ${dateStr}...`));
 		const lockfile = path.join(tmpDir, 'package-lock.json');
 		return readFile(lockfile, { encoding: 'utf-8' });
diff --git a/getProjectTempDir.js b/getProjectTempDir.js
index c5332d9..f3bb4c1 100644
--- a/getProjectTempDir.js
+++ b/getProjectTempDir.js
@@ -13,26 +13,28 @@ const writeFile = promisify(require('fs').writeFile);
 
 const npmNeeded = '^6.9.0-0';
 const pkgContents = {
-	private: true,
+	'private': true,
 	name: 'npm-jail',
 	dependencies: {
-		npm: npmNeeded,
+		npm: npmNeeded
 	}
 };
 
 const cleanupHandlers = [];
-function finalCleanup() {
+const finalCleanup = function finalCleanup() {
 	for (let i = 0; i < cleanupHandlers.length; ++i) {
 		cleanupHandlers[i]();
 	}
-}
+};
 
 let rootTempDir;
-function getRootTempDir(logger = () => {}) {
+const getRootTempDir = function getRootTempDir(logger = () => {}) {
 	if (!rootTempDir) {
 		logger(chalk.blue('Creating root temp directory, to hold temporary lockfiles...'));
 		rootTempDir = new Promise((resolve, reject) => tmp.dir((err, tmpDir, cleanup) => {
-			if (err) { return reject(err); }
+			if (err) {
+				return reject(err);
+			}
 			resolve(tmpDir);
 			cleanupHandlers.push(cleanup);
 			nodeCleanup(finalCleanup);
@@ -44,9 +46,13 @@ function getRootTempDir(logger = () => {}) {
 					path.join(tmpDir, 'package.json'),
 					JSON.stringify(pkgContents)
 				).then(() => new Promise((resolve, reject) => {
-					cleanupHandlers.unshift(() => { rimraf.sync(path.join(tmpDir, '*')); });
-					exec(`npm install --no-package-lock --silent >/dev/null`, { cwd: tmpDir }, (err) => {
-						if (err) { return reject(err); }
+					cleanupHandlers.unshift(() => {
+						rimraf.sync(path.join(tmpDir, '*'));
+					});
+					exec('npm install --no-package-lock --silent >/dev/null', { cwd: tmpDir }, err => {
+						if (err) {
+							return reject(err);
+						}
 						resolve(tmpDir);
 					});
 				}));
@@ -55,13 +61,15 @@ function getRootTempDir(logger = () => {}) {
 		});
 	}
 	return rootTempDir;
-}
+};
 
 module.exports = function getProjectTempDir(logger = undefined) {
 	return getRootTempDir(logger).then(rootDir => {
 		const projectDir = path.join(rootDir, 'XXXXXX');
 		return new Promise((resolve, reject) => tmp.dir({ template: projectDir }, (err, tmpDir, cleanup) => {
-			if (err) { return reject(err); }
+			if (err) {
+				return reject(err);
+			}
 			resolve(tmpDir);
 			cleanupHandlers.unshift(cleanup);
 		}));
diff --git a/package.json b/package.json
index e449ceb..bfd94cb 100644
--- a/package.json
+++ b/package.json
@@ -4,6 +4,8 @@
 	"description": "Safely generate an npm lockfile and output it to the filename of your choice.",
 	"bin": "./bin.js",
 	"scripts": {
+		"lint": "eslint .",
+		"pretest": "npm run lint",
 		"test": "echo \"Error: no test specified\" && exit 1"
 	},
 	"repository": {
@@ -38,5 +40,10 @@
 	},
 	"engines": {
 		"node": ">= 6"
+	},
+	"devDependencies": {
+		"@ljharb/eslint-config": "^13.1.1",
+		"eslint": "^5.14.1",
+		"tape": "^4.10.1"
 	}
 }