diff --git a/README.md b/README.md
index 37ab0e9..bc84715 100644
--- a/README.md
+++ b/README.md
@@ -92,7 +92,7 @@ Some of the application options are not exposed in the GUI. They can be ajusted
 
 | Option | Description |
 | --- | --- |
-| **ActiveClientHighlightThickness** | Thickness of the border used to highlight the active client's thumbnail.<br />Allowed values are **1**, **2**, **3**.<br />The default value is **3**<br />For example: **"ActiveClientHighlightThickness": 3,** |
+| **ActiveClientHighlightThickness** | Thickness of the border used to highlight the active client's thumbnail.<br />Allowed values are **1**...**6**.<br />The default value is **3**<br />For example: **"ActiveClientHighlightThickness": 3,** |
 | **ThumbnailMinimumSize** | Minimum thumbnail size that can be set either via GUI or by resizing a thumbnail window. Value is witten in the form "width, height"<br />The default value is **"100, 80"**.<br />For example: **"ThumbnailMinimumSize": "100, 80",** |
 | **ThumbnailMaximumSize** | Maximum thumbnail size that can be set either via GUI or by resizing a thumbnail window. Value is witten in the form "width, height"<br />The default value is **"640, 400"**.<br />For example: **"ThumbnailMaximumSize": "640, 400",** |