MADISON, Wis. — The state Assembly has sent a bill cracking down on deadly opioids known as fentanyl analogs to Gov. Scott Walker.

The potent drug is being added to heroin, leading to spikes in overdoses across the state. Republican Rep. John Nygren’s daughter, Cassandra Nygren, was charged this month with allegedly providing the fentanyl that killed a pregnant woman.

The bill would add fentanyl analogs to the synthetic opiates category of controlled substances, making it easier for prosecutors to go after manufacturers. Possessing, manufacturing or dealing a fentanyl analog would be a felony.

The Assembly passed the bill in June. The Senate approved it on Tuesday but added four more analog forms to the bill. The Assembly approved the changes on a voice vote Thursday, sending the bill to Walker.