diff --git a/docs/reference/gtk/Makefile.am b/docs/reference/gtk/Makefile.am
index ce6d6e2533..fa0dcb9dc5 100644
--- a/docs/reference/gtk/Makefile.am
+++ b/docs/reference/gtk/Makefile.am
@@ -172,6 +172,7 @@ IGNORE_HFILES = \
 	gtktoolbarprivate.h		\
 	gtktoolpaletteprivate.h		\
 	gtktooltipprivate.h		\
+	gtktooltipwindowprivate.h	\
 	gtktreeprivate.h		\
 	gtkwidgetprivate.h		\
 	gtkwin32themeprivate.h		\