On a 4-1 vote Monday, the Maryville City Council voted to restrict bar access to only those 21 and over.
Some bar owners in attendance spoke out against the ordinance before the vote, concerned with how it would affect their business.
They said while there are sometimes problems with minors in the bars, it Is less of a problem than there would be with minors attending unsupervised house parties.
In the end, Maryville's mayor said it was a matter of health and perception.
"It did become a health matter with me," said mayor Jim Wall. "Although age entry is not a health matter, the whole environment that it seems to condone is a health matter."
The new bar ordinance will take effect in July and affect those businesses where more than half their revenue comes from alcohol sales.
The ordinance was just one part of a comprehensive look at Maryville alcohol policies.
Other alcohol policies the Council is researching include drinking in public and requiring servers of alcohol to get permits.