The ar ticle discusses how the Khuddakanikāya became a par t of the Pāli Tipiṭaka. In my book, Jōzabu Bukkyō no shisō keisei (Formation of Theravāda Buddhist Thought), I note that the Khuddakanikāya does not appear as a collection of suttantas in the four parts of the Pāli commentaries (Aṭṭhakathā) which refer to structure of the Pāli Tipiṭaka. Based on this assessment, I concluded that the Khuddakanikāya was the last collection added to the Pāli Tipiṭaka. In an article published in 2016, the scholar Toshifumi Shimizu critiqued my conclusion, insisting that the four parts of Pāli commentaries, which my book dealt with, do, in fact, mention the Khuddakanikāya. Reassessing these Pāli commentaries, I argue that Shimizu's hypothesis is not valid because it is based on cer tain misunderstandings of Pāli words, and their context, and, on account of more general flaws in the logic informing his critique.