diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 15fe1b9..a6f406f 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -12,7 +12,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [10.x, 12.x, 14.x]
+        node-version: [12.x, 14.x, 16.x]
 
     steps:
     - uses: actions/checkout@v2
@@ -26,3 +26,4 @@ jobs:
     - run: npm run lint
     - run: npm test
     - run: npm run build
+    - run: npm run test-imports
diff --git a/README.md b/README.md
index f5ccdd1..9fd6644 100644
--- a/README.md
+++ b/README.md
@@ -14,12 +14,12 @@ npm i mmdb-lib
 
 ```typescript
 import fs from 'fs';
-import Reader from 'mmdb-lib';
+import * as mmdb from 'mmdb-lib';
 
 // Get a buffer with mmdb database, from file system or whereever.
 const db = fs.readFileSync('/path/to/GeoLite2-City.mmdb');
 
-const reader = new Reader<CityResponse>(db);
+const reader = new mmdb.Reader<CityResponse>(db);
 console.log(reader.get('66.6.44.4')); // inferred type `CityResponse`
 console.log(reader.getWithPrefixLength('66.6.44.4')); // tuple with inferred type `[CityResponse|null, number]`
 ```
diff --git a/package.json b/package.json
index f784e62..514c87e 100644
--- a/package.json
+++ b/package.json
@@ -11,23 +11,24 @@
     "geoip2"
   ],
   "author": "Dmitry Shirokov <deadrunk@gmail.com>",
-  "contributors": [],
-  "dependencies": {},
+  "contributors": [
+    "William Storey @horgh"
+  ],
   "devDependencies": {
     "@types/ip-address": "5.8.2",
-    "@types/jest": "26.0.4",
-    "@types/node": "10.17.5",
+    "@types/jest": "27.0.0",
+    "@types/node": "16.0.0",
     "@types/sinon": "7.5.2",
     "@typescript-eslint/eslint-plugin": "^4.4.0",
     "@typescript-eslint/parser": "^4.4.0",
     "eslint": "^7.10.0",
     "ip-address": "6.2.0",
-    "jest": "26.1.0",
+    "jest": "^27.4.7",
     "prettier": "^2.1.2",
-    "semantic-release": "17.1.1",
+    "semantic-release": "^18.0.1",
     "sinon": "9.0.1",
-    "ts-jest": "26.1.1",
-    "typescript": "3.9.6"
+    "ts-jest": "^27.1.2",
+    "typescript": "4.5.4"
   },
   "repository": {
     "type": "git",
@@ -52,6 +53,7 @@
     "lint": "eslint . --ext .ts",
     "lint:types": "tsc --noEmit",
     "test": "jest",
+    "test-imports": "node test/imports/commonjs.js && node test/imports/esm.mjs",
     "format": "prettier --write src",
     "prepublish": "npm run build",
     "semantic-release": "semantic-release"
diff --git a/src/__test__/integration.test.ts b/src/__test__/integration.test.ts
index 31e2caf..df8ad36 100755
--- a/src/__test__/integration.test.ts
+++ b/src/__test__/integration.test.ts
@@ -2,7 +2,7 @@ import fs from 'fs';
 import assert from 'assert';
 import ipAddr from 'ip-address';
 import path from 'path';
-import Reader from '../';
+import { Reader } from '../';
 import { Cache } from '../types';
 import { Response } from '../reader/response';
 
diff --git a/src/decoder.ts b/src/decoder.ts
index 31e0c32..4d9aa4b 100755
--- a/src/decoder.ts
+++ b/src/decoder.ts
@@ -163,7 +163,7 @@ export default class Decoder {
     // If the value is 30, then the size is 285 + *the next two bytes after the type
     // specifying bytes as a single unsigned integer*.
     if (size === 30) {
-      return cursor(285 + this.db.readUInt16BE(offset, false), offset + 2);
+      return cursor(285 + this.db.readUInt16BE(offset), offset + 2);
     }
 
     // At this point `size` is always 31.
@@ -227,7 +227,7 @@ export default class Decoder {
       // bytes as a 32-bit value. In this case, the last three bits of the control byte
       // are ignored.
     } else {
-      packed = this.db.readUInt32BE(offset, true);
+      packed = this.db.readUInt32BE(offset);
     }
 
     offset += pointerSize + 1;
@@ -252,11 +252,11 @@ export default class Decoder {
   }
 
   private decodeDouble(offset: number) {
-    return this.db.readDoubleBE(offset, true);
+    return this.db.readDoubleBE(offset);
   }
 
   private decodeFloat(offset: number) {
-    return this.db.readFloatBE(offset, true);
+    return this.db.readFloatBE(offset);
   }
 
   private decodeMap(size: number, offset: number) {
@@ -280,7 +280,7 @@ export default class Decoder {
     if (size === 0) {
       return 0;
     }
-    return this.db.readInt32BE(offset, true);
+    return this.db.readInt32BE(offset);
   }
 
   private decodeUint(offset: number, size: number) {
@@ -325,8 +325,7 @@ export default class Decoder {
     const numberOfLongs = size / 4;
     for (let i = 0; i < numberOfLongs; i++) {
       integer =
-        integer * BigInt(4294967296) +
-        BigInt(buffer.readUInt32BE(i << 2, true));
+        integer * BigInt(4294967296) + BigInt(buffer.readUInt32BE(i << 2));
     }
 
     return integer.toString();
diff --git a/src/index.test.ts b/src/index.test.ts
index 8e0e9bb..5a656c5 100644
--- a/src/index.test.ts
+++ b/src/index.test.ts
@@ -1,7 +1,7 @@
 import assert from 'assert';
 import fs from 'fs';
 import path from 'path';
-import Reader from '.';
+import { Reader } from '.';
 
 const dataDir = path.join(__dirname, '../test/data/test-data');
 const read = (dir: string, filepath: string): Buffer =>
diff --git a/src/index.ts b/src/index.ts
index 16ea84e..831a684 100755
--- a/src/index.ts
+++ b/src/index.ts
@@ -7,7 +7,7 @@ import { ReaderOptions } from './types';
 
 const DATA_SECTION_SEPARATOR_SIZE = 16;
 
-export default class Reader<T extends Response> {
+export class Reader<T extends Response> {
   public metadata: Metadata;
   private decoder: Decoder;
   private db: Buffer;
diff --git a/src/reader/walker.ts b/src/reader/walker.ts
index 996d4da..27884e0 100644
--- a/src/reader/walker.ts
+++ b/src/reader/walker.ts
@@ -40,12 +40,12 @@ const readNodeRight28 =
 const readNodeLeft32 =
   (db: Buffer): NodeReader =>
   (offset: number): number =>
-    db.readUInt32BE(offset, true);
+    db.readUInt32BE(offset);
 
 const readNodeRight32 =
   (db: Buffer): NodeReader =>
   (offset: number): number =>
-    db.readUInt32BE(offset + 4, true);
+    db.readUInt32BE(offset + 4);
 
 export default (db: Buffer, recordSize: number): Walker => {
   switch (recordSize) {
diff --git a/test/imports/commonjs.js b/test/imports/commonjs.js
new file mode 100644
index 0000000..904868d
--- /dev/null
+++ b/test/imports/commonjs.js
@@ -0,0 +1,10 @@
+const fs = require('fs');
+const assert = require('assert');
+
+const mmdb = require('../../lib/index.js');
+const db = fs.readFileSync('test/data/test-data/GeoIP2-City-Test.mmdb')
+
+const reader = new mmdb.Reader(db)
+const res = reader.get('175.16.199.255');
+assert.strictEqual(res.city.geoname_id, 2038180);
+console.log('commonjs: OK');
diff --git a/test/imports/esm.mjs b/test/imports/esm.mjs
new file mode 100644
index 0000000..0e5d345
--- /dev/null
+++ b/test/imports/esm.mjs
@@ -0,0 +1,9 @@
+import fs from 'fs';
+import assert from 'assert';
+import * as mmdb from '../../lib/index.js';
+const db = fs.readFileSync('test/data/test-data/GeoIP2-City-Test.mmdb')
+
+const reader = new mmdb.Reader(db)
+const res = reader.get('175.16.199.255');
+assert.strictEqual(res.city.geoname_id, 2038180);
+console.log('esm: OK');
diff --git a/tsconfig.json b/tsconfig.json
index 6b1ecbf..dfbf40a 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,22 +1,14 @@
 {
   "compilerOptions": {
-    "forceConsistentCasingInFileNames": true,
-    "outDir": "lib",
-    "rootDir": "src",
-    "allowJs": false,
-    "allowSyntheticDefaultImports": true,
-    "declaration": true,
-    "diagnostics": true,
-    "esModuleInterop": true,
-    "extendedDiagnostics": true,
-    "listEmittedFiles": true,
+    "lib": ["es2021"],
     "module": "commonjs",
-    "removeComments": true,
-    "sourceMap": true,
+    "target": "es2021",
+    "outDir": "lib",
+
     "strict": true,
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
     "strictPropertyInitialization": false,
-    "lib": ["ES2019"],
-    "target": "ES2019"
   },
   "exclude": [
     "node_modules",