diff --git a/src/Umbraco.Web.Common/Extensions/UmbracoApplicationBuilder.Identity.cs b/src/Umbraco.Web.Common/Extensions/UmbracoApplicationBuilder.Identity.cs
index d456c39fcb..64fde06ac8 100644
--- a/src/Umbraco.Web.Common/Extensions/UmbracoApplicationBuilder.Identity.cs
+++ b/src/Umbraco.Web.Common/Extensions/UmbracoApplicationBuilder.Identity.cs
@@ -1,3 +1,4 @@
+using System;
 using Microsoft.AspNetCore.Identity;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;