diff --git a/package.json b/package.json
index 21077b41..50afd36b 100644
--- a/package.json
+++ b/package.json
@@ -9,6 +9,7 @@
     "test": "aegir test",
     "test:node": "aegir test -t node",
     "test:browser": "aegir test -t browser",
+    "test:types": "npx tsc",
     "build": "aegir build",
     "release": "aegir release",
     "release-minor": "aegir release --type minor",
@@ -39,6 +40,10 @@
     "varint": "^5.0.0"
   },
   "devDependencies": {
+    "@types/chai": "^4.2.8",
+    "@types/dirty-chai": "^2.0.2",
+    "@types/mocha": "^7.0.1",
+    "@types/node": "^13.7.0",
     "aegir": "^20.0.0",
     "bundlesize": "~0.18.0",
     "chai": "^4.2.0",
diff --git a/src/convert.js b/src/convert.js
index e5998381..5a9b4031 100644
--- a/src/convert.js
+++ b/src/convert.js
@@ -183,7 +183,7 @@ function onion32buf (str) {
 function buf2onion (buf) {
   const addrBytes = buf.slice(0, buf.length - 2)
   const portBytes = buf.slice(buf.length - 2)
-  const addr = base32.encode(addrBytes).toString('ascii').toLowerCase()
+  const addr = base32.encode(addrBytes).toLowerCase()
   const port = buf2port(portBytes)
   return addr + ':' + port
 }
diff --git a/src/index.d.ts b/src/index.d.ts
new file mode 100644
index 00000000..56a02e5e
--- /dev/null
+++ b/src/index.d.ts
@@ -0,0 +1,185 @@
+/// <reference types="node" />
+
+declare interface NetOptions {
+  family: 'ipv4' | 'ipv6';
+  host: string;
+  transport: string;
+  port: number;
+}
+
+declare interface Protocol {
+  code: number;
+  size: number;
+  name: string;
+  resolvable: boolean;
+  path: boolean;
+}
+
+declare interface Protocols {
+  table: [number, number, string, boolean?, boolean?][];
+  names: Record<string, Protocol>;
+  codes: Record<number, Protocol>;
+  object(code: number, size: number, name: string, resolvable?: any, path?: any): Protocol;
+}
+
+declare interface NodeAddress {
+  family: 4 | 6;
+  address: string;
+  port: number;
+}
+
+declare type MultiaddrInput = string | Buffer | Multiaddr;
+
+declare class Multiaddr {
+  /**
+   * Creates a [multiaddr](https://github.com/multiformats/multiaddr) from
+   * a Buffer, String or another Multiaddr instance
+   * public key.
+   * @param addr - If String or Buffer, needs to adhere
+   * to the address format of a [multiaddr](https://github.com/multiformats/multiaddr#string-format)
+   */
+  constructor(addr?: MultiaddrInput);
+
+  /**
+   * Returns Multiaddr as a String
+   */
+  toString(): string;
+
+  /**
+   * Returns Multiaddr as a JSON encoded object
+   */
+  toJSON(): string;
+
+  /**
+   * Returns Multiaddr as a convinient options object to be used with net.createConnection
+   */
+  toOptions(): NetOptions;
+
+  /**
+   * Returns Multiaddr as a human-readable string
+   */
+  inspect(): string;
+
+  /**
+   * Returns the protocols the Multiaddr is defined with, as an array of objects, in
+   * left-to-right order. Each object contains the protocol code, protocol name,
+   * and the size of its address space in bits.
+   * [See list of protocols](https://github.com/multiformats/multiaddr/blob/master/protocols.csv)
+   */
+  protos(): Protocol[];
+
+  /**
+   * Returns the codes of the protocols in left-to-right order.
+   * [See list of protocols](https://github.com/multiformats/multiaddr/blob/master/protocols.csv)
+   */
+  protoCodes(): number[];
+
+  /**
+   * Returns the names of the protocols in left-to-right order.
+   * [See list of protocols](https://github.com/multiformats/multiaddr/blob/master/protocols.csv)
+   */
+  protoNames(): string[];
+
+  /**
+   * Returns a tuple of parts
+   */
+  tuples(): [number, Buffer][];
+
+  /**
+   * Returns a tuple of string/number parts
+   */
+  stringTuples(): [number, string | number][];
+
+  /**
+   * Encapsulates a Multiaddr in another Multiaddr
+   */
+  encapsulate(addr: MultiaddrInput): Multiaddr;
+
+  /**
+   * Decapsulates a Multiaddr from another Multiaddr
+   */
+  decapsulate(addr: MultiaddrInput): Multiaddr;
+
+  /**
+   * A more reliable version of `decapsulate` if you are targeting a
+   * specific code, such as 421 (the `p2p` protocol code). The last index of the code
+   * will be removed from the `Multiaddr`, and a new instance will be returned.
+   * If the code is not present, the original `Multiaddr` is returned.
+   */
+  decapsulateCode(code: number): Multiaddr;
+
+  /**
+   * Extract the peerId if the multiaddr contains one
+   */
+  getPeerId(): string;
+
+  /**
+   * Extract the path if the multiaddr contains one
+   */
+  getPath(): string | null;
+
+  /**
+   * Checks if two Multiaddrs are the same
+   */
+  equals(addr: Multiaddr): boolean;
+
+  /**
+   * Gets a Multiaddrs node-friendly address object. Note that protocol information
+   * is left out: in Node (and most network systems) the protocol is unknowable
+   * given only the address.
+   *
+   * Has to be a ThinWaist Address, otherwise throws error
+   */
+  nodeAddress(): NodeAddress;
+
+  /**
+   * Returns if a Multiaddr is a Thin Waist address or not.
+   *
+   * Thin Waist is if a Multiaddr adheres to the standard combination of:
+   *
+   * `{IPv4, IPv6}/{TCP, UDP}`
+   */
+  isThinWaistAddress(addr?: Multiaddr): boolean;
+}
+
+declare interface MultiaddrClass {
+  /**
+   * Creates a [multiaddr](https://github.com/multiformats/multiaddr) from
+   * a Buffer, String or another Multiaddr instance
+   * public key.
+   * @param addr - If String or Buffer, needs to adhere
+   * to the address format of a [multiaddr](https://github.com/multiformats/multiaddr#string-format)
+   */
+  (addr?: MultiaddrInput): Multiaddr;
+
+  /**
+   * Creates a Multiaddr from a node-friendly address object
+   */
+  fromNodeAddress(addr: NodeAddress, transport: string): Multiaddr;
+
+  /**
+   * Object containing table, names and codes of all supported protocols.
+   * To get the protocol values from a Multiaddr, you can use
+   * [`.protos()`](#multiaddrprotos),
+   * [`.protoCodes()`](#multiaddrprotocodes) or
+   * [`.protoNames()`](#multiaddrprotonames)
+   */
+  protocols: Protocols;
+
+  /**
+   * Returns if something is a Multiaddr
+   */
+  isMultiaddr(addr: unknown): addr is Multiaddr;
+
+  /**
+   * Returns if something is a Multiaddr that is a name
+   */
+  isName(addr: Multiaddr): boolean;
+
+  /**
+   * Returns an array of multiaddrs, by resolving the multiaddr that is a name
+   */
+  resolve(addr: Multiaddr): Promise<Multiaddr[]>
+}
+
+export = MultiaddrClass;
diff --git a/tsconfig.json b/tsconfig.json
new file mode 100644
index 00000000..68ec1c02
--- /dev/null
+++ b/tsconfig.json
@@ -0,0 +1,38 @@
+
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "target": "ES5",
+        "noImplicitAny": false,
+        "noImplicitThis": true,
+        "strictFunctionTypes": true,
+        "strictNullChecks": true,
+        "esModuleInterop": true,
+        "resolveJsonModule": true,
+        "allowJs": true,
+        "checkJs": true,
+        "baseUrl": ".",
+        "paths": {
+            "multiaddr": [
+                "./src",
+                "../src",
+            ]
+        },
+        "types": [
+            "node",
+            "mocha",
+            "chai"
+        ],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "./src/index.d.ts",
+    ],
+    "include": [
+        "./test/**/*.spec.js"
+    ]
+}