diff --git a/README.md b/README.md
index dd44370..46f8156 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@ Each row reads **start -> end**, for example `Orgrimmar -> Undercity`, with a li
 
 See the [changelog](CHANGELOG.md) for what changed in each version.
 
-OctoBus needs one extra file, `ZepSense.dll`, which you install by hand in the game folder. Your launcher can install the addon but not the DLL. See [Install](#install).
+OctoBus needs (optional) one extra file, `ZepSense.dll`, which you install by hand in the game folder. Your launcher can install the addon but not the DLL. See [Install](#install).
 
 ## Screenshots