Although fully obsolete everywhere in the Cyrillic world by the 19th century, the letter zelo was revived in 1944 by the designers of the alphabet of the then-codified Macedonian language.

[1] In the early 21st century, the same letter also appeared in Vojislav Nikčević's proposal for the new alphabet for the modern Montenegrin language.

In the Old Slavic period the difference between ⟨Ѕ⟩ and ⟨З⟩ had already begun to be blurred, and in the written Church Slavonic language from the middle of the 17th century ⟨Ѕ⟩ was used only formally.

In the initial version of Russian civil script of Tsar Peter I (1708), the ⟨Ѕ⟩ was assigned the sound /z/, and the letter ⟨З⟩ was removed.

A commission formed to standardise the Macedonian language and orthography decided to adopt the letter on December 4, 1944, after a vote of 10-1.

⟨ѕ⟩ was also used to the middle of the 19th century in the Serbian civil script, whose orthography was closer to Church Slavonic (compared to Russian).

Vuk Karadžić's Serbian Cyrillic alphabet (1868) did not include ⟨ѕ⟩, instead favouring a simple digraph ⟨дз⟩ to represent the sound, as it was non-native.

Marin Drinov, one of the most important players in the establishment of Standard Bulgarian, floated the idea of using ⟨ѕ⟩ as it was found in most dialects, however chose not to as he considered the letter all but forgotten.