Common-envelope ejectability in binaries with a massive donor (M_ZAMS = 10 − 40 M_⊙) and a low-mass secondary of 1.0 M_⊙, shown for two metallicites that are the most relevant for the Milky Way. Notation is the same as in Fig. 2, except that the Y-axis shows orbital period instead of the donor radius and the color indicates the post-CE orbital separation a_post-CE estimated from the energy budget (Sect. 2.3) without the accretion term ΔE_acc. Separations a_post-CE ≈ 4 − 10 R_⊙ are in line with the formation of the observed population of short-period BH-LMXBs (Kalogera 1999; Repetto & Nelemans 2015).