diff --git a/gtk/gtksettings.c b/gtk/gtksettings.c
index 1aa52b6ff5..e44f35d11a 100644
--- a/gtk/gtksettings.c
+++ b/gtk/gtksettings.c
@@ -75,6 +75,8 @@
  * On Wayland, the settings are obtained either via a settings portal,
  * or by reading desktop settings from DConf.
  *
+ * On macOS, the settings are obtained from `NSUserDefaults`.
+ *
  * In the absence of these sharing mechanisms, GTK reads default values for
  * settings from `settings.ini` files in `/etc/gtk-4.0`, `$XDG_CONFIG_DIRS/gtk-4.0`
  * and `$XDG_CONFIG_HOME/gtk-4.0`. These files must be valid key files (see