diff --git a/aspnetcore/fundamentals/configuration/index.md b/aspnetcore/fundamentals/configuration/index.md
index dc6a55318f..4571351fe4 100644
--- a/aspnetcore/fundamentals/configuration/index.md
+++ b/aspnetcore/fundamentals/configuration/index.md
@@ -859,6 +859,7 @@ An <xref:Microsoft.AspNetCore.Hosting.IHostingStartup> implementation allows add
 ## Additional resources
 
 * [Configuration source code](https://github.com/dotnet/runtime/tree/main/src/libraries/Microsoft.Extensions.Configuration)
+* [WebApplicationBuilder source code](https://github.com/dotnet/aspnetcore/blob/v6.0.1/src/DefaultBuilder/src/WebApplicationBuilder.cs)
 * <xref:fundamentals/configuration/options>
 * <xref:blazor/fundamentals/configuration>
 
diff --git a/aspnetcore/fundamentals/index.md b/aspnetcore/fundamentals/index.md
index 33b0bb4be9..30e3fbc15d 100644
--- a/aspnetcore/fundamentals/index.md
+++ b/aspnetcore/fundamentals/index.md
@@ -222,6 +222,10 @@ In Razor *.cshtml* files, tilde-slash (`~/`) points to the web root. A path begi
 
 For more information, see <xref:fundamentals/static-files>.
 
+## Additional resources
+
+* [WebApplicationBuilder source code](https://github.com/dotnet/aspnetcore/blob/v6.0.1/src/DefaultBuilder/src/WebApplicationBuilder.cs)
+
 ::: moniker-end
 
 ::: moniker range="< aspnetcore-6.0"