Is their a way to disable the whats new tab window that pops up after an update?

So I'm helping sort out an individual who is '''very''' ''computer illiterate'' and I'm getting them to use Firefox.. but when it updates, the window that tells you what's new pops up... now this is helpful for most! but for this individual it really confuses them and they tend to call me about it every time... so I'm wondering if their is a way to disable the popup window, to make it less confusing for them without disabling the updates entirely?