Hi LuaTeX Team, I am writing to report strange behavior of the \magstep0 command , or the original magnification \csname @m\endcsname. The problem is happened in a macro with \afterassignment and then assign \magstep0 to a count register. For the LuaTeX version: luatex --version This is LuaTeX, Version 1.22.0 (TeX Live 2026/dev/Arch Linux) Development id: 7674 Execute 'luatex --credits' for credits and version details. There is NO warranty. Redistribution of this software is covered by the terms of the GNU General Public License, version 2 or (at your option) any later version. For more information about these matters, see the file named COPYING and the LuaTeX source. LuaTeX is Copyright 2025 Taco Hoekwater and the LuaTeX Team. The problem is happened in a macro with \afterassignment and then assign \magstep0 to a count register. A shortest description: ``` \newcount\count \def\problemhere#1\relax#2{\string#1#2} \def\todo{ \afterassignment\problemhere \count= } ``` For the above macro, \todo\magstep1{HERE} just print HERE while \todo\magstep0{HERE} print \or1200HERE. It seems that \magstep0 break the \ifcase structure in the \magstep definition, It seems that this is not a expected behavior. Complete use case steps and more details are on the stackoverflow page * https://tex.stackexchange.com/q/745864/248249 Sincerely, Yours