In this article, I examine how Ukrainian humor about Ukrainian and Russian languages shapes and strengthens the identities and internal unity of Ukrainians and helps establish the normativity of language practices among the distributors of humor during the current war in Ukraine. My research is based on interactionist and pragmatic approaches and incongruity theory. Russia's full-scale invasion of Ukraine has brought the language issue to the forefront, especially after Vladimir Putin's claim of “protecting Russian-speakers in Ukraine” as the reason for the aggression. Ukrainian humor helps play out a communicative act, during which the imaginary ridiculed Russian-speaking interlocutor does not understand or misunderstands the Ukrainian language. This is an act of self-assertion with the help of humor, a response to the Russian statements that the Ukrainian language does not exist. Such humor also contributes to establishing a new culture of vigilance necessary at the beginning of a war