diff --git a/samples/server/petstore/nodejs-express-server/controllers/Controller.js b/samples/server/petstore/nodejs-express-server/controllers/Controller.js
index a4115d01438..48b8bb9e97e 100644
--- a/samples/server/petstore/nodejs-express-server/controllers/Controller.js
+++ b/samples/server/petstore/nodejs-express-server/controllers/Controller.js
@@ -43,7 +43,7 @@ class Controller {
   static collectFile(request, fieldName) {
     let uploadedFileName = '';
     if (request.files && request.files.length > 0) {
-      const fileObject = request.files.find(file => file.fieldname === fieldName);
+      const fileObject = request.files.find((file) => file.fieldname === fieldName);
       if (fileObject) {
         const fileArray = fileObject.originalname.split('.');
         const extension = fileArray.pop();
@@ -70,7 +70,7 @@ class Controller {
 
   static collectRequestParams(request) {
     const requestParams = {};
-    if (request.openapi.schema.requestBody !== undefined) {
+    if (request.openapi.schema.requestBody !== null) {
       const { content } = request.openapi.schema.requestBody;
       if (content['application/json'] !== undefined) {
         const requestBodyName = camelCase(this.getRequestBodyName(request));
@@ -89,15 +89,17 @@ class Controller {
       }
     }
 
-    request.openapi.schema.parameters.forEach((param) => {
-      if (param.in === 'path') {
-        requestParams[param.name] = request.openapi.pathParams[param.name];
-      } else if (param.in === 'query') {
-        requestParams[param.name] = request.query[param.name];
-      } else if (param.in === 'header') {
-        requestParams[param.name] = request.headers[param.name];
-      }
-    });
+    if (request.openapi.schema.parameters !== undefined) {
+      request.openapi.schema.parameters.forEach((param) => {
+        if (param.in === 'path') {
+          requestParams[param.name] = request.openapi.pathParams[param.name];
+        } else if (param.in === 'query') {
+          requestParams[param.name] = request.query[param.name];
+        } else if (param.in === 'header') {
+          requestParams[param.name] = request.headers[param.name];
+        }
+      });
+    }
     return requestParams;
   }
 
diff --git a/samples/server/petstore/nodejs-express-server/expressServer.js b/samples/server/petstore/nodejs-express-server/expressServer.js
index 948a912415a..5746e083245 100644
--- a/samples/server/petstore/nodejs-express-server/expressServer.js
+++ b/samples/server/petstore/nodejs-express-server/expressServer.js
@@ -8,7 +8,7 @@ const express = require('express');
 const cors = require('cors');
 const cookieParser = require('cookie-parser');
 const bodyParser = require('body-parser');
-const { OpenApiValidator } = require('express-openapi-validator');
+const OpenApiValidator = require('express-openapi-validator');
 const logger = require('./logger');
 const config = require('./config');
 
@@ -32,11 +32,11 @@ class ExpressServer {
     this.app.use(express.json());
     this.app.use(express.urlencoded({ extended: false }));
     this.app.use(cookieParser());
-    //Simple test to see that the server is up and responding
+    // Simple test to see that the server is up and responding
     this.app.get('/hello', (req, res) => res.send(`Hello World. path: ${this.openApiPath}`));
-    //Send the openapi document *AS GENERATED BY THE GENERATOR*
+    // Send the openapi document *AS GENERATED BY THE GENERATOR*
     this.app.get('/openapi', (req, res) => res.sendFile((path.join(__dirname, 'api', 'openapi.yaml'))));
-    //View the openapi document in a visual interface. Should be able to test from this page
+    // View the openapi document in a visual interface. Should be able to test from this page
     this.app.use('/api-docs', swaggerUI.serve, swaggerUI.setup(this.schema));
     this.app.get('/login-redirect', (req, res) => {
       res.status(200);
@@ -46,30 +46,28 @@ class ExpressServer {
       res.status(200);
       res.json(req.query);
     });
+    this.app.use(
+      OpenApiValidator.middleware({
+        apiSpec: this.openApiPath,
+        operationHandlers: path.join(__dirname),
+        fileUploader: { dest: config.FILE_UPLOAD_PATH },
+      }),
+    );
   }
 
   launch() {
-    new OpenApiValidator({
-      apiSpec: this.openApiPath,
-      operationHandlers: path.join(__dirname),
-      fileUploader: { dest: config.FILE_UPLOAD_PATH },
-    }).install(this.app)
-      .catch(e => console.log(e))
-      .then(() => {
-        // eslint-disable-next-line no-unused-vars
-        this.app.use((err, req, res, next) => {
-          // format errors
-          res.status(err.status || 500).json({
-            message: err.message || err,
-            errors: err.errors || '',
-          });
-        });
-
-        http.createServer(this.app).listen(this.port);
-        console.log(`Listening on port ${this.port}`);
+    // eslint-disable-next-line no-unused-vars
+    this.app.use((err, req, res, next) => {
+      // format errors
+      res.status(err.status || 500).json({
+        message: err.message || err,
+        errors: err.errors || '',
       });
-  }
+    });
 
+    http.createServer(this.app).listen(this.port);
+    console.log(`Listening on port ${this.port}`);
+  }
 
   async close() {
     if (this.server !== undefined) {
diff --git a/samples/server/petstore/nodejs-express-server/package.json b/samples/server/petstore/nodejs-express-server/package.json
index 331d819aa69..e2144704196 100644
--- a/samples/server/petstore/nodejs-express-server/package.json
+++ b/samples/server/petstore/nodejs-express-server/package.json
@@ -19,7 +19,7 @@
     "cookie-parser": "^1.4.4",
     "cors": "^2.8.5",
     "express": "^4.16.4",
-    "express-openapi-validator": "^3.9.1",
+    "express-openapi-validator": "^4.13.8",
     "js-yaml": "^3.3.0",
     "ono": "^5.0.1",
     "openapi-sampler": "^1.0.0-beta.15",