diff --git a/parser.c b/parser.c
index e2eabc1..0dddd78 100644
--- a/parser.c
+++ b/parser.c
@@ -1042,7 +1042,7 @@ static bool parser_sy_apply_operator(parser_t *parser, shunt *sy)
                 else
                     assignop = type_storep_instr[exprs[0]->expression.vtype];
                 if (assignop == AINSTR_END ||
-                    !ast_compare_type(field->expression.next, exprs[1]))
+                    (exprs[1]->expression.vtype != TYPE_NIL && !ast_compare_type(field->expression.next, exprs[1])))
                 {
                     ast_type_to_string(field->expression.next, ty1, sizeof(ty1));
                     ast_type_to_string(exprs[1], ty2, sizeof(ty2));