diff -r 8d6af6ab7d4d -r 21ff9c1a4644 src/Pure/GUI/gui.scala
--- a/src/Pure/GUI/gui.scala	Sun Nov 29 21:58:40 2020 +0100
+++ b/src/Pure/GUI/gui.scala	Sun Nov 29 23:23:32 2020 +0100
@@ -251,6 +251,7 @@
     val default_font = label_font()
     val ui = UIManager.getDefaults
     for (prop <- List(
+      "ToggleButton.font",
       "CheckBoxMenuItem.font",
       "Label.font",
       "Menu.font",