Turning off flyspell programmatically for source blocks in Org mode

[Leo Alekseyev]

When I use Flyspell with org-mode, it often insists on spell-checking
my code, which is nice, but annoying.  How might one prevent flyspell
from operating on code blocks in org, given that they are clearly
delimited with lines #+begin_src [language] and #+end_src?

I've tried adding ("+begin_src" . "+end_src") to
ispell-skip-region-alist, but it didn't seem to work.

Appreciate any suggestions!