diff --git a/source/texk/web2c/luatexdir/font/tounicode.c b/source/texk/web2c/luatexdir/font/tounicode.c
index f0449aff9..4ce912273 100644
--- a/source/texk/web2c/luatexdir/font/tounicode.c
+++ b/source/texk/web2c/luatexdir/font/tounicode.c
@@ -514,7 +514,7 @@ int write_cid_tounicode(PDF pdf, fo_entry * fo, internal_font_number f)
                 if (quick_char_exists(k, i) && char_used(k, i)) {
                     j = char_index(k, i);
                     if (gtab[j].code == UNI_UNDEF) {
-                        set_cid_glyph_unicode(i, &gtab[j], f);
+                        set_cid_glyph_unicode(i, &gtab[j], k);
                     }
                 }
             }