Abelian quotients of extriangulated categories

We prove that certain subquotient categories of extriangulated categories are abelian. As a particular case, if an extriangulated category \(\mathscr {C}\) has a cluster-tilting subcategory \(\mathscr {X}\), then \(\mathscr {C}/\mathscr {X}\) is abelian. This unifies a result by Koenig and Zhu (Math. Z. 258 (2008) 143–160) for triangulated categories and a result by Demonet and Liu (J. Pure Appl. Algebra 217(12) (2013) 2282–2297) for exact categories.