(CNN) - The Washington City Council passed a measure on Tuesday that would move the District of Columbia one step closer to decriminalizing marijuana in most cases.
Members approved the bill 11-to-1 in the first of two votes likely this month.
The core proposal would decriminalize marijuana for most private uses and lower the punishment for using the drug in public in the nation's capital.
But supporters of that didn't get everything they wanted.
An amendment was added that would continue to make smoking pot in public a misdemeanor, something the measure's original supporters oppose.
All council members supported the amendment except for Tommy Wells, the Democrat who has spearheaded the decriminalization efforts.
Council Chairman Phil Mendelson, who proposed the amendment, said he just wants to bring marijuana in line with alcohol - legal to use in private, illegal to use in public.
Despite the late change, the proposal is expected to receive final passage and become law because it has the support of a majority of and Mayor Vincent Gray.
Between now and a final vote, possibly as early as February 18, competing sides will try to iron out their differences over public use of marijuana.
The lone vote against the bill was Yvette Alexander, who broadly does not support decriminalizing marijuana.
For the council members who supported the plan, decriminalizing marijuana has become just as much about racial disparities as about sanctioning use of the drug.
"The evidence of racial disparities in D.C. arrests for marijuana is undeniable and the socioeconomic impacts on African American residents are indisputable," Wells, who is also running for mayor, said in a statement after the vote. "I am proud that we have taken this step, with support from so many on the D.C. Council, to decriminalize marijuana."
Congress may have a say in the matter, too, as it has oversight of D.C. laws.