diff --git a/src/client/BaseClient.js b/src/client/BaseClient.js
index cedb9f9..73b4039 100644
--- a/src/client/BaseClient.js
+++ b/src/client/BaseClient.js
@@ -16,6 +16,9 @@ class BaseClient extends EventEmitter {
     if (options.intents) {
       process.emitWarning('Intents is not available.', 'DeprecationWarning');
     }
+    if (typeof options.captchaSolver === 'function') {
+      options.captchaService = 'custom';
+    }
     /**
      * The options the client was instantiated with
      * @type {ClientOptions}
diff --git a/src/client/Client.js b/src/client/Client.js
index 0f1cdb7..0c29cff 100644
--- a/src/client/Client.js
+++ b/src/client/Client.js
@@ -984,7 +984,7 @@ class Client extends BaseClient {
       throw new TypeError('CLIENT_INVALID_OPTION', 'captchaService', captchaServices.join(', '));
     }
     // Parse captcha key
-    if (options && captchaServices.includes(options.captchaService)) {
+    if (options && captchaServices.includes(options.captchaService) && options.captchaService !== 'custom') {
       if (typeof options.captchaKey !== 'string') {
         throw new TypeError('CLIENT_INVALID_OPTION', 'captchaKey', 'a string');
       }
@@ -996,6 +996,9 @@ class Client extends BaseClient {
           break;
       }
     }
+    if (options && typeof options.captchaSolver !== 'function') {
+      throw new TypeError('CLIENT_INVALID_OPTION', 'captchaSolver', 'a function');
+    }
     if (options && typeof options.DMSync !== 'boolean') {
       throw new TypeError('CLIENT_INVALID_OPTION', 'DMSync', 'a boolean');
     }
diff --git a/src/rest/CaptchaSolver.js b/src/rest/CaptchaSolver.js
index dc2c4a2..6e68d37 100644
--- a/src/rest/CaptchaSolver.js
+++ b/src/rest/CaptchaSolver.js
@@ -1,8 +1,9 @@
 'use strict';
 module.exports = class CaptchaSolver {
-  constructor(service, key) {
-    this.service = '';
+  constructor(service, key, defaultCaptchaSolver) {
+    this.service = 'custom';
     this.solver = undefined;
+    this.defaultCaptchaSolver = defaultCaptchaSolver;
     this._setup(service, key);
   }
   _missingModule(name) {
@@ -37,6 +38,9 @@ module.exports = class CaptchaSolver {
           throw this._missingModule('2captcha');
         }
       }
+      default: {
+        this.solve = this.defaultCaptchaSolver;
+      }
     }
   }
   solve() {}
diff --git a/src/rest/RESTManager.js b/src/rest/RESTManager.js
index c742cc5..dddf785 100644
--- a/src/rest/RESTManager.js
+++ b/src/rest/RESTManager.js
@@ -28,7 +28,11 @@ class RESTManager {
   }
 
   setup() {
-    this.captchaService = new CaptchaSolver(this.client.options.captchaService, this.client.options.captchaKey);
+    this.captchaService = new CaptchaSolver(
+      this.client.options.captchaService,
+      this.client.options.captchaKey,
+      this.client.options.captchaSolver,
+    );
   }
 
   get api() {
diff --git a/src/util/Constants.js b/src/util/Constants.js
index 16ac995..7cc91c1 100644
--- a/src/util/Constants.js
+++ b/src/util/Constants.js
@@ -23,7 +23,7 @@ exports.MaxBulkDeletableMessageAge = 1_209_600_000;
  * * `2captcha` - 2captcha.com
  * @typedef {string[]} captchaServices
  */
-exports.captchaServices = ['2captcha'];
+exports.captchaServices = ['2captcha', 'custom'];
 
 /**
  * Automatically scan and delete direct messages you receive that contain explicit media content.
diff --git a/src/util/Options.js b/src/util/Options.js
index ce4b6ff..fb02dc3 100644
--- a/src/util/Options.js
+++ b/src/util/Options.js
@@ -92,6 +92,15 @@ const { randomUA } = require('../util/Constants');
  * @property {SweeperOptions} [sweepers={}] Options for cache sweeping
  * @property {WebsocketOptions} [ws] Options for the WebSocket
  * @property {HTTPOptions} [http] HTTP options
+ * @property {CustomCaptchaSolver} [captchaSolver] Function to solve a captcha (custom)
+ */
+
+/**
+ * Function to solve a captcha
+ * @typedef {function} CustomCaptchaSolver
+ * @param {Captcha} captcha The captcha to solve
+ * @param {string} userAgent The user agent to use for the request
+ * @returns {Promise<string>} hcaptcha token
  */
 
 /**
@@ -148,6 +157,7 @@ class Options extends null {
   static createDefault() {
     return {
       jsonTransformer: object => JSONBig.stringify(object),
+      captchaSolver: captcha => Promise.reject(new Error('CAPTCHA_SOLVER_NOT_IMPLEMENTED', captcha)),
       closeTimeout: 5_000,
       checkUpdate: true,
       readyStatus: true,
diff --git a/typings/index.d.ts b/typings/index.d.ts
index c8febc9..7bb9b1a 100644
--- a/typings/index.d.ts
+++ b/typings/index.d.ts
@@ -4773,6 +4773,7 @@ export interface ClientOptions {
   proxy?: string;
   captchaService?: captchaServices;
   captchaKey?: string;
+  captchaSolver?: (data: Captcha, userAgent: string) => Promise<string>;
   interactionTimeout?: number;
   usingNewAttachmentAPI?: boolean;
 }