## Steps to upgrade
Follow the steps below to upgrade your Optimizely Content Management System (CMS 8) project to the latest MVC version.
Upgrade your site to the latest NuGet package for [ASP.NET MVC](🔗), run "Update-Package Microsoft.AspNet.Mvc" in the Package Manager Console.
Update the application **web.config** file in your project as follows: \- Change the **System.Web.Mvc** version number from "4.0.0.0" to "5.0.0.0". \- Change the **System.Web.Helpers** and **System.Web.WebPages** version number from "2.0.0.0" to "3.0.0.0" (if not already done). If **System.Web.WebPages.Razor** exist as a dependent assembly it should also have version "3.0.0.0". \- Change the **webpages:Version** in the **<appSettings>** section from 2.0.0.0.0 to 3.0.0.0. The result should look like:
Update the **web.config** file in the **Views** folder as follows: \- Update elements containing **System.Web.Mvc** from version "4.0.0.0" to "5.0.0.0". \- Update elements containing **System.Web.WebPages.Razor** from version "2.0.0.0" to "3.0.0.0".
If you use Web API 1, run "Install-Package Microsoft.AspNet.WebApi.WebHost" in the Package Manager Console to update your global.asax from:
to:
Build your solution and verify that the site is working.
## See also
[How to upgrade an ASP.NET MVC 4 and Web API Project to ASP.NET MVC 5 and Web API 2](🔗) (Microsoft)