diff --git a/package.json b/package.json
index 86c29525..7849794f 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,7 @@
     "dist"
   ],
   "scripts": {
-    "prepare": "aegir build",
+    "prepare": "aegir build --no-bundle",
     "lint": "aegir lint",
     "test:browser": "aegir test --target browser",
     "test:node": "aegir test --target node",
@@ -41,12 +41,12 @@
   "repository": "github:multiformats/js-multihash",
   "dependencies": {
     "multibase": "^3.1.0",
-    "uint8arrays": "^1.0.0",
+    "uint8arrays": "^2.0.5",
     "varint": "^6.0.0"
   },
   "devDependencies": {
-    "aegir": "^29.0.1",
-    "ipfs-utils": "^5.0.0"
+    "aegir": "^30.3.0",
+    "ipfs-utils": "^5.0.1"
   },
   "eslintConfig": {
     "extends": "ipfs"
diff --git a/src/constants.js b/src/constants.js
index 29fb7d4c..5790415b 100644
--- a/src/constants.js
+++ b/src/constants.js
@@ -13,7 +13,7 @@
  */
 
 /**
- * @type { Object<HashName,HashCode> }
+ * @type { Record<HashName,HashCode> }
  */
 const names = Object.freeze({
   'identity': 0x00,
diff --git a/src/index.js b/src/index.js
index 5b0a4dd2..09809c08 100644
--- a/src/index.js
+++ b/src/index.js
@@ -16,7 +16,8 @@ const codes = /** @type {import('./types').CodeNameMap} */({})
 
 // eslint-disable-next-line guard-for-in
 for (const key in names) {
-  codes[names[key]] = key
+  const name = /** @type {HashName} */(key)
+  codes[names[name]] = name
 }
 
 /**
@@ -86,7 +87,7 @@ function decode (bytes) {
     throw new Error('multihash too short. must be > 2 bytes.')
   }
 
-  const code = varint.decode(bytes)
+  const code = /** @type {HashCode} */(varint.decode(bytes))
   if (!isValidCode(code)) {
     throw new Error(`multihash unknown function code: 0x${code.toString(16)}`)
   }
@@ -166,6 +167,7 @@ function coerceCode (name) {
     throw new Error(`Hash function code should be a number. Got: ${code}`)
   }
 
+  // @ts-ignore
   if (codes[code] === undefined && !isAppCode(code)) {
     throw new Error(`Unrecognized function code: ${code}`)
   }
diff --git a/src/types.ts b/src/types.ts
index 63df2de5..40e2c21b 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -1,4 +1,4 @@
-import { HashCode, HashName } from './constants.js'
+import type { HashCode, HashName } from './constants.js'
 
 export type CodeNameMap = Record<HashCode, HashName>
 export type NameCodeMap = Record<HashName, HashCode>
diff --git a/test/index.spec.js b/test/index.spec.js
index f39894bf..3d531881 100644
--- a/test/index.spec.js
+++ b/test/index.spec.js
@@ -12,7 +12,20 @@ const uint8ArrayToString = require('uint8arrays/to-string')
 const uint8ArrayFromString = require('uint8arrays/from-string')
 const uint8ArrayEquals = require('uint8arrays/equals')
 
+/**
+ * @typedef {import('../src/constants.js').HashName} HashName
+ * @typedef {import('../src/constants.js').HashCode} HashCode
+ */
+
+/**
+ * @param {string | number} code
+ * @param {number} size
+ * @param {string} hex
+ */
 function sample (code, size, hex) {
+  /**
+   * @param {number | string} i
+   */
   const toHex = (i) => {
     if (typeof i === 'string') {
       return i
@@ -23,6 +36,10 @@ function sample (code, size, hex) {
   return uint8ArrayFromString(`${toHex(code)}${toHex(size)}${hex}`, 'base16')
 }
 
+/**
+ * @param {string} description
+ * @param {(test: { encodeText: (text: string) => Uint8Array, encodeHex: (text: string) => Uint8Array }) => void} test
+ */
 const they = (description, test) => {
   it(description, () => test({
     encodeText: (text) => uint8ArrayFromString(text),
@@ -195,7 +212,7 @@ describe('multihash', () => {
     it('invalid', () => {
       invalidCases.forEach((test) => {
         expect(
-          () => mh.validate(sample(test.encoding.varint || test.code, test.size, test.hex))
+          () => mh.validate(sample(test.code, test.size, test.hex))
         ).to.throw()
       })
 
@@ -257,7 +274,7 @@ describe('multihash', () => {
         false
       )
 
-      for (var m = 0x10; m <= 0xff; m++) {
+      for (let m = 0x10; m <= 0xff; m++) {
         expect(
           mh.isAppCode(m)
         ).to.equal(
@@ -269,17 +286,18 @@ describe('multihash', () => {
 
   describe('coerceCode', () => {
     it('valid', () => {
-      /** @type {Partial<Record<import('../src/constants').HashName, import('../src/constants').HashCode>> } */
       const names = {
         sha1: 0x11,
         'sha2-256': 0x12,
         'sha2-512': 0x13,
         'sha3-512': 0x14
       }
-
-      Object.keys(names).forEach((name) => {
+      /** @type {keyof typeof names} */
+      let name
+      // eslint-disable-next-line guard-for-in
+      for (name in names) {
         expect(
-          mh.coerceCode(/** @type {import('../src/constants.js').HashName} */(name))
+          mh.coerceCode(name)
         ).to.be.eql(
           names[name]
         )
@@ -289,7 +307,7 @@ describe('multihash', () => {
         ).to.be.eql(
           names[name]
         )
-      })
+      }
     })
 
     they('invalid', ({ encodeText }) => {
@@ -309,6 +327,7 @@ describe('multihash', () => {
       })
 
       expect(
+        // @ts-expect-error
         () => mh.coerceCode(encodeText('hello'))
       ).to.throw(
         /should be a number/
diff --git a/tsconfig.json b/tsconfig.json
index e605b61a..c5150deb 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,10 +1,15 @@
 {
     "extends": "./node_modules/aegir/src/config/tsconfig.aegir.json",
     "compilerOptions": {
-        "outDir": "dist"
+        "outDir": "dist",
+        "baseUrl": "./",
+        "paths": {
+          "*": ["./types/*"]
+        }
     },
     "include": [
       "test", // remove this line if you don't want to type-check tests
-      "src"
+      "src",
+      "types"
     ]
 }
diff --git a/types/varint/index.d.ts b/types/varint/index.d.ts
new file mode 100644
index 00000000..108baaff
--- /dev/null
+++ b/types/varint/index.d.ts
@@ -0,0 +1,39 @@
+export const encode: {
+  /**
+   * Encodes `num` into `buffer` starting at `offset`. returns `buffer`, with the encoded varint written into it.
+   * `varint.encode.bytes` will now be set to the number of bytes modified.
+   */
+  (num: number, buffer: Uint8Array, offset?: number): Uint8Array
+
+  /**
+   * Encodes `num` into `array` starting at `offset`. returns `array`, with the encoded varint written into it.
+   * If `array` is not provided, it will default to a new array.
+   * `varint.encode.bytes` will now be set to the number of bytes modified.
+   */
+  (num: number, array?: number[], offset?: number): number[]
+
+  /**
+   * Similar to `decode.bytes` when encoding a number it can be useful to know how many bytes where written (especially if you pass an output array).
+   * You can access this via `varint.encode.bytes` which holds the number of bytes written in the last encode.
+   */
+  bytes: number
+}
+
+export const decode: {
+  /**
+   * Decodes `data`, which can be either a buffer or array of integers, from position `offset` or default 0 and returns the decoded original integer.
+   * Throws a `RangeError` when `data` does not represent a valid encoding.
+   */
+  (buf: Uint8Array | Buffer | number[], offset?: number): number
+
+  /**
+   * If you also require the length (number of bytes) that were required to decode the integer you can access it via `varint.decode.bytes`.
+   * This is an integer property that will tell you the number of bytes that the last .decode() call had to use to decode.
+   */
+  bytes: number
+}
+
+/**
+ * returns the number of bytes this number will be encoded as, up to a maximum of 8.
+ */
+export function encodingLength (num: number): number
diff --git a/update-constants.js b/update-constants.js
index 45dc7870..5f22fec5 100644
--- a/update-constants.js
+++ b/update-constants.js
@@ -43,7 +43,7 @@ const run = async () => {
  */
 
 /**
- * @type { Object<HashName,HashCode> }
+ * @type { Record<HashName,HashCode> }
  */
 const names = Object.freeze({
 ${processed}