diff --git a/packages/common/interfaces/http/http-server.interface.ts b/packages/common/interfaces/http/http-server.interface.ts
index 0fc061455cb..8bf7e49a965 100644
--- a/packages/common/interfaces/http/http-server.interface.ts
+++ b/packages/common/interfaces/http/http-server.interface.ts
@@ -18,7 +18,11 @@ export type RequestHandler<TRequest = any, TResponse = any> = (
   next?: Function,
 ) => any;
 
-export interface HttpServer<TRequest = any, TResponse = any> {
+export interface HttpServer<
+  TRequest = any,
+  TResponse = any,
+  ServerInstance = any,
+> {
   use(
     handler:
       | RequestHandler<TRequest, TResponse>
@@ -69,7 +73,7 @@ export interface HttpServer<TRequest = any, TResponse = any> {
   getRequestHostname?(request: TRequest): string;
   getRequestMethod?(request: TRequest): string;
   getRequestUrl?(request: TRequest): string;
-  getInstance(): any;
+  getInstance(): ServerInstance;
   registerParserMiddleware(...args: any[]): any;
   enableCors(options: CorsOptions | CorsOptionsDelegate<TRequest>): any;
   getHttpServer(): any;
diff --git a/packages/platform-express/interfaces/nest-express-application.interface.ts b/packages/platform-express/interfaces/nest-express-application.interface.ts
index d096c7b166b..cfabd63d9e3 100644
--- a/packages/platform-express/interfaces/nest-express-application.interface.ts
+++ b/packages/platform-express/interfaces/nest-express-application.interface.ts
@@ -1,7 +1,8 @@
 import { Server } from 'http';
-import { INestApplication } from '@nestjs/common';
+import { INestApplication, HttpServer } from '@nestjs/common';
 import * as bodyparser from 'body-parser';
 import { NestExpressBodyParserOptions } from './nest-express-body-parser-options.interface';
+import { Express } from 'express';
 import { ServeStaticOptions } from './serve-static-options.interface';
 
 /**
@@ -12,6 +13,13 @@ import { ServeStaticOptions } from './serve-static-options.interface';
  * @publicApi
  */
 export interface NestExpressApplication extends INestApplication {
+  /**
+   * Returns the underlying HTTP adapter bounded to the Express.js app.
+   *
+   * @returns {HttpServer}
+   */
+  getHttpAdapter(): HttpServer<Express.Request, Express.Response, Express>;
+
   /**
    * Starts the application.
    *
diff --git a/packages/platform-fastify/interfaces/nest-fastify-application.interface.ts b/packages/platform-fastify/interfaces/nest-fastify-application.interface.ts
index 26b106516dd..16569631eaa 100644
--- a/packages/platform-fastify/interfaces/nest-fastify-application.interface.ts
+++ b/packages/platform-fastify/interfaces/nest-fastify-application.interface.ts
@@ -1,4 +1,4 @@
-import { INestApplication } from '@nestjs/common';
+import { INestApplication, HttpServer } from '@nestjs/common';
 import {
   FastifyBodyParser,
   FastifyInstance,
@@ -6,6 +6,8 @@ import {
   FastifyPluginCallback,
   FastifyPluginOptions,
   FastifyRegisterOptions,
+  FastifyRequest,
+  FastifyReply,
   RawServerBase,
 } from 'fastify';
 import {
@@ -20,6 +22,13 @@ import { NestFastifyBodyParserOptions } from './nest-fastify-body-parser-options
  * @publicApi
  */
 export interface NestFastifyApplication extends INestApplication {
+  /**
+   * Returns the underlying HTTP adapter bounded to a Fastify app.
+   *
+   * @returns {HttpServer}
+   */
+  getHttpAdapter(): HttpServer<FastifyRequest, FastifyReply, FastifyInstance>;
+
   /**
    * A wrapper function around native `fastify.register()` method.
    * Example `app.register(require('@fastify/formbody'))