This article examines a printed booklet from Mombasa, written in Swahili in Arabic script and titled Mwalimu wa watoto (“Children's Teacher”). The booklet was written by Shaykh al-Amin b. ‘Ali Mazru‘i, a pioneer of East African Islamic reformism, and serves as a handbook that concisely and accessibly explains the basics of Islam to children. This example of ‘Ajami writing, which was discovered by the author in Mombasa, has not previously been studied. It provides a lens through which to examine the ethno-cultural, religious, and social dimensions of ‘Ajami script usage in colonial Kenya. The shift from the Arabic to the Latin script, driven by the British authorities and missionary influence, raised concerns among local Muslim thinkers about the “Christianisation” of Swahili and the erosion of its Islamic elements. Thus, the use of ‘Ajami script is regarded as a means to assert religious and cultural identity. The writing and publishing of Islamic literature for children, alongside encouraging independent study of religious fundamentals, reflected the educational aims of East African Muslim reformers. They sought not only to equip children with Islamic knowledge but also to critique Sufi shaykhs, whom they accused of practices resembling pagan rituals.