Hi Bastien, The issue is that currently tangling a single block by calling `org-babel-tangle` with a prefix argument fails. This is unrelated to the earlier thread today, but was introduced by my original commit a2cb9b853d. Unfortunately, fixing it requires some refactorisation to avoid code duplication. To keep the patch as simple as possible, I have introduced a new helper function, I hope this is okay. I have tested the attached patch with the uses cases shown so far, as well as my own and the org test suite. I apologise again for the troubles. -- Sébastien Miquel