diff --git a/Lib/idlelib/util.py b/Lib/idlelib/util.py
index bdf02892de68ea9..e884e38bef90bf1 100644
--- a/Lib/idlelib/util.py
+++ b/Lib/idlelib/util.py
@@ -24,7 +24,7 @@
 def fix_scaling(root):  # Called in filelist _test, pyshell, and run.
     """Scale fonts on HiDPI displays, once per process."""
     import tkinter.font
-    scaling = root.tk_scaling()
+    scaling = root.tk_scaling()  # tkinter method new in 3.16
     if scaling > 1.4:
         for name in tkinter.font.names(root):
             font = tkinter.font.Font(root=root, name=name, exists=True)