diff --git a/src/xinit.c b/src/xinit.c
index 54bcf83f..6193d260 100644
--- a/src/xinit.c
+++ b/src/xinit.c
@@ -2640,6 +2640,8 @@ int Tcl_AppInit(Tcl_Interp *inter)
 
 /* pass to tcl values of Alt, Shift, COntrol key masks so bind Alt-KeyPress events will work for windows */
 #ifndef __unix__
+ my_snprintf(tmp, S(tmp), "%d", Mod4Mask);
+ tclsetvar("Mod4Mask", tmp);
  my_snprintf(tmp, S(tmp), "%d", Mod1Mask);
  tclsetvar("Mod1Mask", tmp);
  my_snprintf(tmp, S(tmp), "%d", ShiftMask);
diff --git a/src/xschem.tcl b/src/xschem.tcl
index c1cf947f..cd9efc0c 100644
--- a/src/xschem.tcl
+++ b/src/xschem.tcl
@@ -5784,6 +5784,11 @@ global env has_x OS autofocus_mainwindow
   
     # on Windows Alt key mask is reported as 131072 (1<<17) so build masks manually with values passed from C code 
     if {$OS == "Windows" } {
+      bind $topwin <Mod4-KeyPress> {xschem callback %W %T %x %y 0 %b 0 [expr {$Mod4Mask}]}
+      bind $topwin <Shift-Mod4-KeyPress> {xschem callback %W %T %x %y 0 %b 0 [expr {$ShiftMask + $Mod4Mask}]}
+      bind $topwin <Control-Mod4-KeyPress> {xschem callback %W %T %x %y 0 %b 0 [expr {$ControlMask + $Mod4Mask}]}
+      bind $topwin <Alt-Mod4-KeyPress> {xschem callback %W %T %x %y 0 %b 0 [expr {$Mod1Mask + $Mod4Mask}]}
+      bind $topwin <Mod4-KeyPress> {xschem callback %W %T %x %y 0 %b 0 [expr {$Mod4Mask}]}
       bind $topwin <Alt-ButtonPress> {xschem callback %W %T %x %y 0 %b 0 [expr {$Mod1Mask}]}
       bind $topwin <Control-Alt-ButtonPress> {xschem callback %W %T %x %y 0 %b 0 [expr {$ControlMask + $Mod1Mask}]}
       bind $topwin <Shift-Alt-ButtonPress> {xschem callback %W %T %x %y 0 %b 0 [expr {$ShiftMask + $Mod1Mask}]}