1 files changed, 1 insertions, 0 deletions

diff --git a/src/dispextern.h b/src/dispextern.h
index e030618a9b7..679820d5063 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -3293,6 +3293,7 @@ extern void dump_glyph_string (struct glyph_string *) EXTERNALLY_VISIBLE;
 
 extern void x_get_glyph_overhangs (struct glyph *, struct frame *,
                                    int *, int *);
+extern struct font *font_for_underline_metrics (struct glyph_string *);
 extern void x_produce_glyphs (struct it *);
 
 extern void x_write_glyphs (struct window *, struct glyph_row *,