diff --git a/.github/workflows/main_ci.yml b/.github/workflows/main_ci.yml
index be16be1..9be5d43 100644
--- a/.github/workflows/main_ci.yml
+++ b/.github/workflows/main_ci.yml
@@ -13,7 +13,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 20
           registry-url: https://registry.npmjs.org/
       - run: npm ci
       - run: npm run unit
@@ -23,7 +23,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 20
           registry-url: https://registry.npmjs.org/
       - run: npm ci
       - run: npm run coverage
@@ -33,7 +33,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 20
           registry-url: https://registry.npmjs.org/
       - run: npm ci
       - run: npm run format:ci
@@ -43,7 +43,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 20
           registry-url: https://registry.npmjs.org/
       - run: npm ci
       - run: npm run gitdiff:ci
@@ -53,7 +53,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 20
           registry-url: https://registry.npmjs.org/
       - run: npm ci
       - run: npm run lint
@@ -63,7 +63,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v4
         with:
-          node-version: 18
+          node-version: 20
           registry-url: https://registry.npmjs.org/
       - run: npm ci
       - run: npm run lint:tests
diff --git a/fixup.cjs b/fixup.cjs
index a776270..91b1830 100755
--- a/fixup.cjs
+++ b/fixup.cjs
@@ -9,6 +9,14 @@ const updateRequires = (filePath) => {
   fs.writeFileSync(filePath, content, 'utf8');
 };
 
+const updateImports = (filePath) => {
+  let content = fs.readFileSync(filePath, 'utf8');
+  //replace local imports eg. from './types'; to from './types.js';
+  content = content.replace(/from '\.\/([^']*)'/g, "from './$1.js'");
+
+  fs.writeFileSync(filePath, content, 'utf8');
+};
+
 const processFiles = (dir) => {
   fs.readdirSync(dir).forEach((file) => {
     const filePath = path.join(dir, file);
@@ -16,9 +24,11 @@ const processFiles = (dir) => {
       processFiles(filePath);
     } else if (filePath.endsWith('.cjs')) {
       updateRequires(filePath);
+    } else if (filePath.endsWith('.js')) {
+      updateImports(filePath);
     }
   });
 };
 
-const dir = path.join(__dirname, 'src', 'cjs');
+const dir = path.join(__dirname, 'src');
 processFiles(dir);
diff --git a/src/cjs/ecpair.cjs b/src/cjs/ecpair.cjs
index 4315477..b27d44a 100644
--- a/src/cjs/ecpair.cjs
+++ b/src/cjs/ecpair.cjs
@@ -115,6 +115,17 @@ function ECPairFactory(ecc) {
       network: network,
     });
   }
+  /**
+   * Generates a random ECPairInterface.
+   *
+   * Uses `crypto.getRandomValues` under the hood for options.rng function, which is still an experimental feature as of Node.js 18.19.0. To work around this you can do one of the following:
+   * 1. Use a polyfill for crypto.getRandomValues()
+   * 2. Use the `--experimental-global-webcrypto` flag when running node.js.
+   * 3. Pass in a custom rng function to generate random values.
+   *
+   * @param {ECPairOptions} options - Options for the ECPairInterface.
+   * @return {ECPairInterface} A random ECPairInterface.
+   */
   function makeRandom(options) {
     v.parse(ECPairOptionsSchema, options);
     if (options === undefined) options = {};
diff --git a/src/esm/ecpair.js b/src/esm/ecpair.js
index 1eb5751..54faab8 100644
--- a/src/esm/ecpair.js
+++ b/src/esm/ecpair.js
@@ -1,7 +1,7 @@
-import * as networks from './networks';
-import * as types from './types';
+import * as networks from './networks.js';
+import * as types from './types.js';
 import * as wif from 'wif';
-import { testEcc } from './testecc';
+import { testEcc } from './testecc.js';
 export { networks };
 import * as v from 'valibot';
 import * as tools from 'uint8array-tools';
@@ -67,6 +67,17 @@ export function ECPairFactory(ecc) {
       network: network,
     });
   }
+  /**
+   * Generates a random ECPairInterface.
+   *
+   * Uses `crypto.getRandomValues` under the hood for options.rng function, which is still an experimental feature as of Node.js 18.19.0. To work around this you can do one of the following:
+   * 1. Use a polyfill for crypto.getRandomValues()
+   * 2. Use the `--experimental-global-webcrypto` flag when running node.js.
+   * 3. Pass in a custom rng function to generate random values.
+   *
+   * @param {ECPairOptions} options - Options for the ECPairInterface.
+   * @return {ECPairInterface} A random ECPairInterface.
+   */
   function makeRandom(options) {
     v.parse(ECPairOptionsSchema, options);
     if (options === undefined) options = {};
diff --git a/src/esm/index.js b/src/esm/index.js
index ad66e7b..d0e793d 100644
--- a/src/esm/index.js
+++ b/src/esm/index.js
@@ -1 +1 @@
-export { ECPairFactory as default, ECPairFactory, networks } from './ecpair';
+export { ECPairFactory as default, ECPairFactory, networks } from './ecpair.js';
diff --git a/test/ecpair.spec.ts b/test/ecpair.spec.ts
index c2c7ad9..e03231a 100644
--- a/test/ecpair.spec.ts
+++ b/test/ecpair.spec.ts
@@ -1,8 +1,8 @@
 import * as assert from 'assert';
 import { createHash } from 'crypto';
 import { beforeEach, describe, it } from 'mocha';
-import { ECPairFactory, networks as NETWORKS } from 'ecpair';
-import type { ECPairInterface, TinySecp256k1Interface } from 'ecpair';
+import { ECPairFactory, networks as NETWORKS } from '..';
+import type { ECPairInterface, TinySecp256k1Interface } from '..';
 import fixtures from './fixtures/ecpair.json';
 import * as tinysecp from 'tiny-secp256k1';
 import * as tools from 'uint8array-tools';
diff --git a/ts_src/ecpair.ts b/ts_src/ecpair.ts
index 8fcc519..2cd9902 100644
--- a/ts_src/ecpair.ts
+++ b/ts_src/ecpair.ts
@@ -157,7 +157,7 @@ export function ECPairFactory(ecc: TinySecp256k1Interface): ECPairAPI {
 
   /**
    * Generates a random ECPairInterface.
-   * 
+   *
    * Uses `crypto.getRandomValues` under the hood for options.rng function, which is still an experimental feature as of Node.js 18.19.0. To work around this you can do one of the following:
    * 1. Use a polyfill for crypto.getRandomValues()
    * 2. Use the `--experimental-global-webcrypto` flag when running node.js.