Explanations of the long ī in the Old Gutnish tīa ʻtoe’ (>ModGu täiå) have been put forward that posit different ablaut grades than the Proto-Germanic *taihwōn which underlies the forms found in other Germanic languages. This is because it was thought the Old Gutnish form could not reflect the standard proto-form. This paper concludes on the basis of the parallel development of *slaihwōn ʻsloe berry’, which appears as ModGu släiå, that long ī can in fact continue the Proto-Germanic sequence *-aihw- as the result of regular sound development.