We examined first language (L1) naming of common household objects in three groups of Russian–English bilinguals: early, childhood and late bilinguals. Their naming patterns were compared with those of native speakers of Russian and English, in order to detect possible second language (L2) English influence on L1 Russian naming patterns. We investigated whether such influence is modulated by the speaker's linguistic trajectory, specifically, their age of arrival in the L2 environment, which in turn influences their relative proficiency and dominance in the two languages. We also examined whether the potential for L2 shifts can be linked to specific characteristics of the categories in the L1 or L2. L2 influence was evident in the data, increasing with earlier age of arrival but most pronounced with lowest L1 proficiency. The changes entailed both narrowing and broadening of linguistic categories. These findings indicate that L1 word use is susceptible to L2 influence even for concrete nouns referring to familiar objects, and the nature of the shift for a given word appears to be driven by several factors.