The article deals with the problem of writing double consonants in borrowed words in modern Russian as part of the complex problem of adapting borrowed words. Double consonants, or the contact spelling of two identical consonant letters, are generally not characteristic of the native vocabulary of the Russian language, however, consonant doubling is quite common in both old and new borrowings. The problem seems relevant due to the fact that it is unsolved both in theoretical and practical terms. Borrowings are currently sporadic, and often a unit borrowed into the Russian language contains as many doubled consonants as the original word, despite the fact that linguists warn against writing borrowed words with a single or double consonant only on the basis of comparing the borrowed word with the lexeme of the original language. It is proposed to distinguish between cases of using double consonants based on the "spelling shell" of the word in the source language and cases of using double consonants that reflect the real pronunciation of the word in the donor language, as well as to unify the rule of writing double consonants in new borrowed words, leaving the traditional spellings of long-mastered borrowings.