Index: doc/text.n
==================================================================
--- doc/text.n
+++ doc/text.n
@@ -2220,13 +2220,12 @@
 after copying it to the clipboard.
 .IP [31]
 Control-t reverses the order of the two characters to the right of
 the insertion cursor.
 .IP [32]
-Control-z (and Control-underscore on UNIX when \fBtk_strictMotif\fR is
-true) undoes the last edit action if the \fB\-undo\fR option is true.
-Does nothing otherwise.
+Control-z undoes the last edit action if the \fB\-undo\fR option is
+true. Does nothing otherwise.
 .IP [33]
 Control-Z (or Control-y on Windows) reapplies the last undone edit
 action if the \fB\-undo\fR option is true. Does nothing otherwise.
 .PP
 If the widget is disabled using the \fB\-state\fR option, then its

Index: library/tk.tcl
==================================================================
--- library/tk.tcl
+++ library/tk.tcl
@@ -306,11 +306,10 @@
     }
 
     event $op <<Cut>> <Control-Key-w>
     event $op <<Copy>> <Meta-Key-w> 
     event $op <<Paste>> <Control-Key-y>
-    event $op <<Undo>> <Control-underscore>
 }
 
 #----------------------------------------------------------------------
 # Define common dialogs on platforms where they are not implemented using
 # compiled code.