diff --git a/src/Umbraco.Core/Sync/ApplicationUrlHelper.cs b/src/Umbraco.Core/Sync/ApplicationUrlHelper.cs
index d0a4c53db7..a417ec601a 100644
--- a/src/Umbraco.Core/Sync/ApplicationUrlHelper.cs
+++ b/src/Umbraco.Core/Sync/ApplicationUrlHelper.cs
@@ -142,7 +142,8 @@ namespace Umbraco.Core.Sync
                 ? ":" + request.ServerVariables["SERVER_PORT"]
                 : "";
 
-            var ssl = GlobalSettings.UseSSL ? "s" : ""; // force, whatever the first request
+            var useSsl = GlobalSettings.UseSSL || port == "443";
+            var ssl = useSsl ? "s" : ""; // force, whatever the first request
             var url = "http" + ssl + "://" + request.ServerVariables["SERVER_NAME"] + port + IOHelper.ResolveUrl(SystemDirectories.Umbraco);
 
             appContext._umbracoApplicationUrl = url.TrimEnd('/');