diff --git a/gtk/linphone.h b/gtk/linphone.h
index 865b0bc7a..764663508 100644
--- a/gtk/linphone.h
+++ b/gtk/linphone.h
@@ -364,6 +364,7 @@ LINPHONE_PUBLIC void linphone_gtk_reload_sound_devices(void);
 LINPHONE_PUBLIC void linphone_gtk_reload_video_devices(void);
 LINPHONE_PUBLIC bool_t linphone_gtk_is_friend(LinphoneCore *lc, const char *contact);
 LINPHONE_PUBLIC gboolean linphone_gtk_auto_answer_enabled(void);
+LINPHONE_PUBLIC void linphone_gtk_auto_answer_delay_changed(GtkSpinButton *spinbutton, gpointer user_data);
 LINPHONE_PUBLIC void linphone_gtk_update_status_bar_icons(void);
 LINPHONE_PUBLIC void linphone_gtk_enable_auto_answer(GtkToggleButton *checkbox, gpointer user_data);