Singer Melissa Etheridge has endorsed gay marriage in Maryland.

Etheridge said everyone deserves to be treated equally under the law in an email sent to supporters of Marylanders for Marriage Equality, the group working to uphold a gay marriage law approved by lawmakers.

“Two of my dearest friends are Marylanders in a committed relationship without legal protection,” Etheridge said. “They are not treated with the same basic equality as their next door neighbors. You can help change that in November.”

The Baltimore Sun reported that Etheridge was referring to Maryland State Delegate Heather Mizeur and her partner Deborah. Mizieur was among the openly gay lawmakers to call on colleagues to approve marriage equality.

Other celebrities rallying in support of the measure include Adam Lambert, Mo'Nique, John Waters, Susan Sarandon and Ed Norton.

(Related: Susan Sarandon, John Waters, Ed Norton fundraise for Maryland gay marriage.)

Etheridge is expected to tie in her November 2 4th Street Feeling Tour date in Bethesda with the campaign.

(Related: Adam Lambert: Gay marriage is not a political or religious issue.)