diff --git a/src/errors.h b/src/errors.h
index 537072d..753e2fe 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -684,3 +684,5 @@
 	INIT(= N_("E1243: ASCII code not in 32-127 range"));
 EXTERN char e_bad_color_string_str[]
 	INIT(= N_("E1244: Bad color string: %s"));
+EXTERN char e_cannot_expand_sfile_in_vim9_function[]
+	INIT(= N_("E1245: Cannot expand <sfile> in a Vim9 function"));