This article reconsiders the material of the disappeared Northern Samoyedic idiom, data on which were collected in the 17th century by G.F. Müller and interpreted by E.A. Helimsky. Linguistically, Jurak is included in the group of Northern Samoyed languages, along with Forest and Tundra Enets, Forest and Tundra Nenets, Nganasan and Mator. Geographically, E.A. Helimsky localizes the Jurak language in the northern part of the interfluve of the Taz and Yenisei. It is significant that Jurak is localized between the Entets language in the east and Nenets in the west. E.A. Helimsky showed that from the point of view of historical phonetics, the Jurak language in some respects occupies an intermediate position between Nenets and Enets. He also notes that a number of Jurak words that do not coincide with Nenets have a parallel in Enets. Based on this, he proposed to consider Jurak a Nenets dialect, which shared some of the characteristics of the neighboring closely related language. This paper proposes to revise the data on the historical phonetics of the Jurak language. It is demonstrated that in different Jurak words the development of the same phonemic sequences can have two options. One variant is shared with the rest of the Nenets dialects, whereas the other with the Enets language. This situation indicates that Jurak is not the result of a diachronically consistent development of a peripheral Nenets dialect in contact with Enets, but is a mixed language with Nenets and Enets components.