diff --git a/python-src/batocera-launch-libretro-mame/batocera_launch_libretro_mame/controllers.py b/python-src/batocera-launch-libretro-mame/batocera_launch_libretro_mame/controllers.py
index 87ac21e7638..f3a0312a3a9 100644
--- a/python-src/batocera-launch-libretro-mame/batocera_launch_libretro_mame/controllers.py
+++ b/python-src/batocera-launch-libretro-mame/batocera_launch_libretro_mame/controllers.py
@@ -368,8 +368,8 @@ def write_controllers_config(self) -> None:
                         'standard',
                         'UI_SELECT',
                         'ENTER',
-                        'a',
-                        _RETRO_PAD_MAPPINGS['a'],
+                        'b',
+                        _RETRO_PAD_MAPPINGS['b'],
                     )
 
                 if mess_controls is not None: