diff --git a/ui/drivers/ui_cocoa.m b/ui/drivers/ui_cocoa.m
index d790dda58e..9d710f08b7 100644
--- a/ui/drivers/ui_cocoa.m
+++ b/ui/drivers/ui_cocoa.m
@@ -580,11 +580,11 @@ ui_companion_driver_t ui_companion_cocoa = {
    ui_companion_cocoa_event_command,
    ui_companion_cocoa_notify_content_loaded,
    ui_companion_cocoa_notify_list_pushed,
-   NULL,
-   NULL,
-   NULL,
+   NULL, /* notify_refresh */
+   NULL, /* msg_queue_push */
+   NULL, /* render_messagebox */
    ui_companion_cocoa_get_main_window,
-   NULL,
+   NULL, /* log_msg */
    &ui_browser_window_cocoa,
    &ui_msg_window_cocoa,
    &ui_window_cocoa,
diff --git a/ui/drivers/ui_cocoatouch.m b/ui/drivers/ui_cocoatouch.m
index 5b1ca47f55..04fb6d4065 100644
--- a/ui/drivers/ui_cocoatouch.m
+++ b/ui/drivers/ui_cocoatouch.m
@@ -709,8 +709,8 @@ ui_companion_driver_t ui_companion_cocoatouch = {
    ui_companion_cocoatouch_notify_refresh,
    ui_companion_cocoatouch_msg_queue_push,
    ui_companion_cocoatouch_render_messagebox,
-   NULL,
-   NULL,
+   NULL, /* get_main_window */
+   NULL, /* log_msg */
    &ui_browser_window_null,
    &ui_msg_window_null,
    &ui_window_null,