SACRAMENTO, Calif. (AP) – Changes demanded by California’s governor as a condition of signing a controversial vaccine bill have cleared their first hurdle.

The Assembly passed the companion bill, sending it to the Senate for a vote later Monday.

Gov. Gavin Newsom last week called for more changes to legislation intended to crack down on doctors who sell fraudulent medical exemptions.

Lawmakers sent Newsom that bill last week. But Sen. Richard Pan agreed to carry follow-up legislation giving school children grace periods that could last several years on existing medical exemptions.

The companion bill also makes it clear that enforcement will start next year. It removes a requirement that doctors swear under penalty of perjury that they’re not charging fees to fill out medical exemption forms.

Several opponents were detained for blocking Capitol entrances.