The article is devoted to an analysis of the text of a small dhāraṇī invocation in the manuscript recension of the Mongolian Kanjur that remained unrecorded in the process of cataloguing of the St. Petersburg copy of the canonical collection. It presents the transcription of the text and its duplicates included in two recensions of the Mongolian-language Buddhist Canon as well as the results of textological collation of the dhāraṇī in the extant copies of the Mongolian Kanjur.