diff --git a/aspnetcore/includes/run-the-app.md b/aspnetcore/includes/run-the-app.md
index 346a2f6005..06c153e0c3 100644
--- a/aspnetcore/includes/run-the-app.md
+++ b/aspnetcore/includes/run-the-app.md
@@ -25,4 +25,4 @@
 
 <!-- End of VS tabs -->
 
----
\ No newline at end of file
+---
diff --git a/aspnetcore/includes/trust-ff.md b/aspnetcore/includes/trust-ff.md
new file mode 100644
index 0000000000..9024d21094
--- /dev/null
+++ b/aspnetcore/includes/trust-ff.md
@@ -0,0 +1 @@
+For information on trusting the Firefox browser, see [Firefox SEC_ERROR_INADEQUATE_KEY_USAGE certificate error](xref:security/enforcing-ssl#trust-ff).
\ No newline at end of file
diff --git a/aspnetcore/includes/trustCertVS.md b/aspnetcore/includes/trustCertVS.md
index f7ef4fef67..ec45fa2293 100644
--- a/aspnetcore/includes/trustCertVS.md
+++ b/aspnetcore/includes/trustCertVS.md
@@ -9,3 +9,5 @@ The following dialog is displayed:
 ![Security warning dialog](~/getting-started/_static/cert.png)
 
 Select **Yes** if you agree to trust the development certificate.
+
+[!INCLUDE[trust FF](~/includes/trust-ff.md)]
\ No newline at end of file
diff --git a/aspnetcore/includes/trustCertVSC.md b/aspnetcore/includes/trustCertVSC.md
index cc6c6ae45f..c4c612e01f 100644
--- a/aspnetcore/includes/trustCertVSC.md
+++ b/aspnetcore/includes/trustCertVSC.md
@@ -14,3 +14,4 @@
 
   See [Trust the ASP.NET Core HTTPS development certificate](xref:security/enforcing-ssl#trust-the-aspnet-core-https-development-certificate-on-windows-and-macos) for more information.
   
+[!INCLUDE[trust FF](~/includes/trust-ff.md)]
\ No newline at end of file
diff --git a/aspnetcore/security/enforcing-ssl.md b/aspnetcore/security/enforcing-ssl.md
index 652240a2c6..c6748a549f 100644
--- a/aspnetcore/security/enforcing-ssl.md
+++ b/aspnetcore/security/enforcing-ssl.md
@@ -434,6 +434,20 @@ See [HTTPS Error using IIS Express (dotnet/AspNetCore #16892)](https://github.co
 
 To fix problems with the IIS Express certificate, select **Repair** from the Visual Studio installer. For more information, see [this GitHub issue](https://github.com/dotnet/aspnetcore/issues/16892).
 
+<a name="trust-ff"></a>
+
+### Firefox SEC_ERROR_INADEQUATE_KEY_USAGE certificate error
+
+The Firefox browser uses it's own certificate store, and therefore doesn't trust the [IIS Express](iis/extensions/introduction-to-iis-express/iis-express-overview) or [Kestrel](xref:fundamentals/servers/kestrel) developer certificates.
+
+To use Firefox with IIS Express or Kestrel, set  `security.enterprise_roots.enabled` = `true`
+
+1. Enter `about:config` in the FireFox browser.
+1. Select **Accept the Risk and Continue** if you accept the risk.
+1. Select **Show All**
+1. Set `security.enterprise_roots.enabled` = `true`
+1. Exit and restart Firefox
+
 ## Additional information
 
 * <xref:host-and-deploy/proxy-load-balancer>
diff --git a/aspnetcore/tutorials/razor-pages/razor-pages-start.md b/aspnetcore/tutorials/razor-pages/razor-pages-start.md
index 1d13326f85..cf5b0579de 100644
--- a/aspnetcore/tutorials/razor-pages/razor-pages-start.md
+++ b/aspnetcore/tutorials/razor-pages/razor-pages-start.md
@@ -411,7 +411,6 @@ At the end of this tutorial, you'll have a working Razor Pages web app that you'
 
   Launching the app with <kbd>Ctrl+F5</kbd> (non-debug mode) allows you to make code changes, save the file, refresh the browser, and see the code changes. Many developers prefer to use non-debug mode to quickly launch the app and view changes.
 
-
   [!INCLUDE[](~/includes/trustCertVS.md)]
 
   Visual Studio starts [IIS Express](/iis/extensions/introduction-to-iis-express/iis-express-overview) and runs the app. The address bar shows `localhost:port#` and not something like `example.com`. That's because `localhost` is the standard hostname for the local computer. Localhost only serves web requests from the local computer. When Visual Studio creates a web project, a random port is used for the web server.