diff --git a/package.json b/package.json
index cddb2d5..7a559dd 100644
--- a/package.json
+++ b/package.json
@@ -13,7 +13,7 @@
     "build"
   ],
   "engines": {
-    "node": ">= 14"
+    "node": ">= 14.18.0"
   },
   "scripts": {
     "test": "make clean && make && make pretest && make test",
@@ -23,10 +23,10 @@
     "preversion": "npm run build"
   },
   "devDependencies": {
-    "@types/node": "^16.11.62",
+    "@types/node": "^18.11.18",
     "@types/tar-fs": "^2.0.1",
     "clean-modules": "^2.0.6",
-    "typescript": "^4.8.3"
+    "typescript": "^4.9.4"
   },
   "bugs": {
     "url": "https://github.com/Sparticuz/chromium/issues"
diff --git a/source/index.ts b/source/index.ts
index 3f74607..b7c7769 100644
--- a/source/index.ts
+++ b/source/index.ts
@@ -1,8 +1,8 @@
-import { access, createWriteStream, existsSync, mkdirSync, symlink } from 'fs';
-import { IncomingMessage } from 'http';
+import { access, createWriteStream, existsSync, mkdirSync, symlink } from 'node:fs';
+import { IncomingMessage } from 'node:http';
 import LambdaFS from './lambdafs';
-import { join } from 'path';
-import { URL } from 'url';
+import { join } from 'node:path';
+import { URL } from 'node:url';
 
 /** Viewport taken from https://github.com/puppeteer/puppeteer/blob/main/docs/api/puppeteer.viewport.md */
 interface Viewport {
@@ -37,7 +37,7 @@ interface Viewport {
   hasTouch?: boolean;
 }
 
-if (/^AWS_Lambda_nodejs(?:10|12|14|16|18)[.]x$/.test(process.env.AWS_EXECUTION_ENV) === true) {
+if ( process.env.AWS_EXECUTION_ENV !== undefined && /^AWS_Lambda_nodejs(?:14|16|18)[.]x$/.test(process.env.AWS_EXECUTION_ENV) === true) {
   if (process.env.FONTCONFIG_PATH === undefined) {
     process.env.FONTCONFIG_PATH = '/tmp/aws';
   }
@@ -52,11 +52,13 @@ if (/^AWS_Lambda_nodejs(?:10|12|14|16|18)[.]x$/.test(process.env.AWS_EXECUTION_E
 class Chromium {
   /**
    * Downloads or symlinks a custom font and returns its basename, patching the environment so that Chromium can find it.
-   * If not running on AWS Lambda nor Google Cloud Functions, `null` is returned instead.
+   * If headless is not true, `null` is returned instead.
    */
-  static font(input: string): Promise<string> {
+  static font(input: string): Promise<string | null> {
     if (Chromium.headless !== true) {
-      return null;
+      return new Promise((resolve) => {
+        return resolve(null);
+      });
     }
 
     if (process.env.HOME === undefined) {
@@ -76,7 +78,7 @@ class Chromium {
       const output = `${process.env.HOME}/.fonts/${url.pathname.split('/').pop()}`;
 
       if (existsSync(output) === true) {
-        return resolve(output.split('/').pop());
+        return resolve(output.split('/').pop() as string);
       }
 
       if (url.protocol === 'file:') {
@@ -86,7 +88,7 @@ class Chromium {
           }
 
           symlink(url.pathname, output, (error) => {
-            return error != null ? reject(error) : resolve(url.pathname.split('/').pop());
+            return error != null ? reject(error) : resolve(url.pathname.split('/').pop() as string);
           });
         });
       } else {
@@ -109,7 +111,7 @@ class Chromium {
 
           response.once('end', () => {
             stream.end(() => {
-              return resolve(url.pathname.split('/').pop());
+              return resolve(url.pathname.split('/').pop() as string);
             });
           });
         });
@@ -208,12 +210,12 @@ class Chromium {
       LambdaFS.inflate(`${input}/swiftshader.tar.br`),
     ];
 
-    if (/^AWS_Lambda_nodejs(?:10|12|14|16|18)[.]x$/.test(process.env.AWS_EXECUTION_ENV) === true) {
+    if (process.env.AWS_EXECUTION_ENV !== undefined && /^AWS_Lambda_nodejs(?:14|16|18)[.]x$/.test(process.env.AWS_EXECUTION_ENV) === true) {
       promises.push(LambdaFS.inflate(`${input}/aws.tar.br`));
     }
 
     const result = await Promise.all(promises);
-    return result.shift();
+    return result.shift() as string;
   }
 
   /**
diff --git a/source/lambdafs.ts b/source/lambdafs.ts
index f0cb1f8..de95eab 100644
--- a/source/lambdafs.ts
+++ b/source/lambdafs.ts
@@ -1,8 +1,8 @@
-import { createReadStream, createWriteStream, existsSync } from 'fs';
-import { tmpdir } from 'os';
-import { basename, join } from 'path';
+import { createReadStream, createWriteStream, existsSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { basename, join } from 'node:path';
 import { extract } from 'tar-fs';
-import { createBrotliDecompress, createUnzip } from 'zlib';
+import { createBrotliDecompress, createUnzip } from 'node:zlib';
 
 class LambdaFS {
   /**
diff --git a/tsconfig.json b/tsconfig.json
index 3f3541d..24d1ae7 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,41 +1,18 @@
 {
-  "compileOnSave": false,
   "compilerOptions": {
-    "alwaysStrict": true,
     "declaration": true,
     "declarationDir": "build",
-    "emitDecoratorMetadata": true,
     "esModuleInterop": true,
-    "experimentalDecorators": true,
     "forceConsistentCasingInFileNames": true,
-    "importHelpers": false,
-    "inlineSourceMap": false,
     "lib": ["dom", "es2020"],
-    "listEmittedFiles": false,
-    "listFiles": false,
     "module": "commonjs",
     "moduleResolution": "node",
-    "noFallthroughCasesInSwitch": true,
-    "noImplicitAny": true,
-    "noImplicitReturns": true,
-    "noImplicitThis": true,
-    "noUnusedLocals": false,
-    "noUnusedParameters": false,
     "outDir": "build",
     "pretty": true,
-    "resolveJsonModule": true,
     "skipLibCheck": true,
-    "sourceMap": true,
     "strict": true,
-    "strictFunctionTypes": true,
-    "strictNullChecks": false,
     "target": "es2020",
-    "traceResolution": false,
-    "types": ["node"]
   },
   "exclude": ["build", "node_modules", "tmp"],
-  "include": ["source"],
-  "typeAcquisition": {
-    "enable": true
-  }
+  "include": ["source"]
 }