diff --git a/Lib/lib-tk/Tkconstants.py b/Lib/lib-tk/Tkconstants.py
index ac57952..63eee33 100644
--- a/Lib/lib-tk/Tkconstants.py
+++ b/Lib/lib-tk/Tkconstants.py
@@ -86,6 +86,11 @@
 MULTIPLE='multiple'
 EXTENDED='extended'
 
+# Activestyle for list boxes
+# NONE='none' is also valid
+DOTBOX='dotbox'
+UNDERLINE='underline'
+
 # Various canvas styles
 PIESLICE='pieslice'
 CHORD='chord'