Prevent Tkinter Canvas from resizing

[Eric Wong]

Using Tkinter, I have a Canvas with vertical Scrollbar attached.  At
runtime, I dynamically create Checkboxes on the Canvas, each one on a
different row.  When I add a lot of Checkboxes, instead of the
scrollbar kicking in, the Canvas resizes and subsequently, my
Application window resizes such that it is larger than my monitor.

Can I prevent the Canvas from resizing when I am creating widgets on it
at runtime?  I want to use the scrollbars when there are more
Checkboxes than will fit on the visible Canvas.  Is this possible?
Thanks for any help.