diff --git a/gtk/gtknotebook.h b/gtk/gtknotebook.h
index d02e384e74..d219f78c42 100644
--- a/gtk/gtknotebook.h
+++ b/gtk/gtknotebook.h
@@ -44,8 +44,22 @@ G_BEGIN_DECLS
 #define GTK_NOTEBOOK_PAGE(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GTK_TYPE_NOTEBOOK_PAGE, GtkNotebookPage))
 #define GTK_IS_NOTEBOOK_PAGE(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GTK_TYPE_NOTEBOOK_PAGE))
 
+/**
+ * GtkNotebookPage:
+ *
+ * A page in the #GtkNotebook.
+ *
+ * The `GtkNotebookPage` structure only contains private data.
+ */
 typedef struct _GtkNotebookPage GtkNotebookPage;
 
+/**
+ * GtkNotebookTab:
+ * @GTK_NOTEBOOK_TAB_FIRST: the first tab in the notebook
+ * @GTK_NOTEBOOK_TAB_LAST: the last tab in the notebook
+ *
+ * The parameter used in the action signals of #GtkNotebook.
+ */
 typedef enum
 {
   GTK_NOTEBOOK_TAB_FIRST,