diff --git a/src/ChangeLog b/src/ChangeLog
index b6bc36e10ce..4bf04043ab9 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -27,6 +27,7 @@
 	does not deduce are never used uninitialized.
 	* window.h (check_all_windows): New decl, to forestall
 	gcc -Wmissing-prototypes diagnostic.
+	* dispextern.h (bidi_dump_cached_states): Likewise.
 
 	* charset.h (CHECK_CHARSET_GET_CHARSET): Rename locals to avoid
 	shadowing.
diff --git a/src/dispextern.h b/src/dispextern.h
index 37ae7ee5fd5..30979d487ff 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -2944,6 +2944,7 @@ enum tool_bar_item_image
 
 extern void bidi_init_it (EMACS_INT, EMACS_INT, struct bidi_it *);
 extern void bidi_move_to_visually_next (struct bidi_it *);
+extern void bidi_dump_cached_states (void);
 extern void bidi_paragraph_init (bidi_dir_t, struct bidi_it *, int);
 extern int  bidi_mirror_char (int);