Maryland governor Martin O’Malley has moved to end health-insurance benefits for same-sex partners of state employees after the state voted to recognize same-sex marriage last year. Same-sex couples will now need to get married in order to receive coverage.

While the new policy would affect only about 300 state employees, the Baltimore Sun reports that Maryland officials say the change is necessary as a matter of fairness because health coverage is not offered to unmarried heterosexual couples. An O’Malley spokeswoman said the state could face legal challenges if it doesn’t make the change.

The decision has drawn ire from some gay-rights groups. “We would like to see domestic partnership benefits on the books for same-sex couples until there’s a level playing field with regard to marriage,” Equality Maryland executive director said, arguing that this has not yet occurred because some other states and the federal government don’t recognize same-sex marriage. “It’s really not the most equitable thing to be doing right now.”

Delegate Maggie McIntosh, an openly gay member of the state assembly, believes eliminating coverage for domestic partners was the right move. “In Maryland, we have a level playing field,” she said. “Because we fought for equality, we got equality, we should now be embracing equality.”