diff --git a/gio/gtask.h b/gio/gtask.h
index 7642d2c68..6d7fa82ff 100644
--- a/gio/gtask.h
+++ b/gio/gtask.h
@@ -196,8 +196,10 @@ gboolean      g_task_get_completed             (GTask           *task);
 
 /*< private >*/
 #ifndef __GTK_DOC_IGNORE__
+#ifndef __GI_SCANNER__
 /* Debugging API, not part of the public API */
 void g_task_print_alive_tasks (void);
+#endif /* !__GI_SCANNER__ */
 #endif  /* !__GTK_DOC_IGNORE__ */
 
 G_END_DECLS