diff --git a/cmake/sdlchecks.cmake b/cmake/sdlchecks.cmake
index e6beb7474..f4723b312 100644
--- a/cmake/sdlchecks.cmake
+++ b/cmake/sdlchecks.cmake
@@ -307,7 +307,9 @@ macro(CheckX11)
       sdl_glob_sources("${SDL3_SOURCE_DIR}/src/video/x11/*.c")
       set(SDL_VIDEO_DRIVER_X11 1)
 
-      # !!! FIXME: why is this disabled for Apple?
+      # Note: Disabled on Apple because the dynamic mode backend for X11 doesn't
+      # work properly on Apple during several issues like inconsistent paths
+      # among platforms. See #6778 (https://github.com/libsdl-org/SDL/issues/6778)
       if(APPLE)
         set(SDL_X11_SHARED OFF)
       endif()