diff --git a/README.md b/README.md
index 9e6e234..bbbfef1 100644
--- a/README.md
+++ b/README.md
@@ -63,6 +63,7 @@ Options:
 
     URxvt.urlLauncher:   browser/command to open selected URL with
     URxvt.underlineURLs: if set to true, all URLs get underlined
+    URvxt.urlButton:     mouse button to click-open URLs (default: 2)
 
 
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