diff --git a/Rnwood.Smtp4dev/appsettings.json b/Rnwood.Smtp4dev/appsettings.json
index 4547c6d39..5dca55fcf 100644
--- a/Rnwood.Smtp4dev/appsettings.json
+++ b/Rnwood.Smtp4dev/appsettings.json
@@ -41,7 +41,7 @@
     // Default value: 100
     "NumberOfSessionsToKeep": 100,
 
-    // Specifies the TLS mode to use. Valid options are: None, Auto or StartTls.
+    // Specifies the TLS mode to use. Valid options are: None, StartTls or ImplicitTls.
     // Default value: "None"
     "TlsMode": "None",