diff --git a/HISTORY.md b/HISTORY.md
index 37b16a0f..f099e1b2 100755
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -24,6 +24,7 @@
 * added new "serial ports" library
 * added jshint esversion tags
 * gui: unified palette: don't animate scrolling if delta is zero
+* byob: replaced checkboxes in custom block context menus with symbols
 
 ### 2021-07-04
 * fixed audio_comp library "plot sound" block to work with translations, thanks, Hans, for the report!
diff --git a/src/byob.js b/src/byob.js
index 066a517b..31b27b59 100644
--- a/src/byob.js
+++ b/src/byob.js
@@ -1081,10 +1081,17 @@ CustomCommandBlockMorph.prototype.userMenu = function () {
         menu;
 
     function addOption(label, toggle, test, onHint, offHint) {
-        var on = '\u2611 ',
-            off = '\u2610 ';
         menu.addItem(
-            (test ? on : off) + localize(label),
+            [
+                test ? new SymbolMorph(
+                    'checkedBox',
+                    MorphicPreferences.menuFontSize * 0.75
+                ) : new SymbolMorph(
+                    'rectangle',
+                    MorphicPreferences.menuFontSize * 0.75
+                ),
+                localize(label)
+            ],
             toggle,
             test ? onHint : offHint
         );