diff --git a/docs/reference/gtk/migrating-3to4.xml b/docs/reference/gtk/migrating-3to4.xml
index 9bb310534b..e08d97f316 100644
--- a/docs/reference/gtk/migrating-3to4.xml
+++ b/docs/reference/gtk/migrating-3to4.xml
@@ -199,6 +199,19 @@
+
+ Stop using gtk_main() and related APIs
+
+
+ GTK4 removes the gtk_main_ family of APIs. The recommended replacement
+ is GtkApplication, but you can also iterate the GLib mainloop directly,
+ using GMainContext APIs.
+
+
+ The replacement for gtk_events_pending() is g_main_context_pending(),
+ the replacement for gtk_main_iteration() is g_main_context_iteration().
+
+