diff --git a/package.json b/package.json
index 5d6ee5c..79f82ae 100644
--- a/package.json
+++ b/package.json
@@ -21,7 +21,7 @@
   "main": "src/index.js",
   "repository": "github:multiformats/js-multibase",
   "scripts": {
-    "prepare": "aegir build",
+    "prepare": "aegir build --no-bundle",
     "lint": "aegir lint",
     "test": "aegir test",
     "test:node": "aegir test -t node",
@@ -35,10 +35,10 @@
   },
   "dependencies": {
     "@multiformats/base-x": "^4.0.1",
-    "web-encoding": "^1.0.4"
+    "web-encoding": "^1.0.6"
   },
   "devDependencies": {
-    "aegir": "^29.0.1",
+    "aegir": "^30.3.0",
     "benchmark": "^2.1.4"
   },
   "engines": {
diff --git a/src/index.js b/src/index.js
index 310e597..df66bad 100644
--- a/src/index.js
+++ b/src/index.js
@@ -10,6 +10,7 @@ const { encodeText, decodeText, concat } = require('./util')
 /** @typedef {import('./base')} Base */
 /** @typedef {import("./types").BaseNameOrCode} BaseNameOrCode */
 /** @typedef {import("./types").BaseCode} BaseCode */
+/** @typedef {import("./types").BaseName} BaseName */
 
 /**
  * Create a new Uint8Array with the multibase varint+code.
@@ -113,10 +114,10 @@ function validEncode (name, buf) {
  * @throws {Error} Will throw if the encoding is not supported
  */
 function encoding (nameOrCode) {
-  if (constants.names[nameOrCode]) {
-    return constants.names[nameOrCode]
-  } else if (constants.codes[nameOrCode]) {
-    return constants.codes[nameOrCode]
+  if (constants.names[/** @type {BaseName} */(nameOrCode)]) {
+    return constants.names[/** @type {BaseName} */(nameOrCode)]
+  } else if (constants.codes[/** @type {BaseCode} */(nameOrCode)]) {
+    return constants.codes[/** @type {BaseCode} */(nameOrCode)]
   } else {
     throw new Error(`Unsupported encoding: ${nameOrCode}`)
   }
diff --git a/src/rfc4648.js b/src/rfc4648.js
index 89a1aa2..c911cc1 100644
--- a/src/rfc4648.js
+++ b/src/rfc4648.js
@@ -10,6 +10,7 @@
  */
 const decode = (string, alphabet, bitsPerChar) => {
   // Build the character lookup table:
+  /** @type {Record<string, number>} */
   const codes = {}
   for (let i = 0; i < alphabet.length; ++i) {
     codes[alphabet[i]] = i
diff --git a/src/types.ts b/src/types.ts
index 84438f8..e85a720 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -24,7 +24,7 @@ export type BaseCode =
     | 'm'
     | 'M'
     | 'u'
-    | 'U';
+    | 'U'
 
 /**
  * - Names of the supported encodings
@@ -52,11 +52,11 @@ export type BaseName =
     | 'base64'
     | 'base64pad'
     | 'base64url'
-    | 'base64urlpad';
+    | 'base64urlpad'
 
-export type BaseNameOrCode = BaseCode | BaseName;
-export type Codec = {
-    encode: (buffer: Uint8Array) => string;
-    decode: (hash: string) => Uint8Array;
-};
-export type CodecFactory = (input: string) => Codec;
+export type BaseNameOrCode = BaseCode | BaseName
+export interface Codec {
+  encode: (buffer: Uint8Array) => string
+  decode: (hash: string) => Uint8Array
+}
+export interface CodecFactory { (input: string): Codec }
diff --git a/test/multibase.spec.js b/test/multibase.spec.js
index 9d80cd9..31257f9 100644
--- a/test/multibase.spec.js
+++ b/test/multibase.spec.js
@@ -6,6 +6,7 @@ const { encodeText, decodeText } = require('../src/util')
 const multibase = require('../src')
 const constants = require('../src/constants.js')
 
+/** @type {Array<[BaseName, string, string]>} */
 const unsupportedBases = []
 
 /**
@@ -88,6 +89,10 @@ const supportedBases = [
   ['base64urlpad', '÷ïÿ🥰÷ïÿ😎🥶🤯', 'Uw7fDr8O_8J-lsMO3w6_Dv_CfmI7wn6W28J-krw==']
 ]
 
+/**
+ * @param {string} label
+ * @param {(encodeText:(text: string) => Uint8Array) => void} def
+ */
 const they = (label, def) => {
   it(`${label} (Uint8Array)`, def.bind(null, encodeText))
 }