diff --git a/src/errors.h b/src/errors.h
index 1662043..1dfb9ab 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -3511,5 +3511,7 @@
 	INIT(= N_("E1406: Member \"%s\": type mismatch, expected %s but got %s"));
 EXTERN char e_method_str_type_mismatch_expected_str_but_got_str[]
 	INIT(= N_("E1407: Member \"%s\": type mismatch, expected %s but got %s"));
+EXTERN char e_aptypes_is_null_str_nr[]
+	INIT(= "E1408: Internal error: ap_types or ap_types[idx] is NULL: %d: %s");
 
 // E1371 - E1399 unused