The Department of Education is no longer counting outdoor trailers as part of a school's classroom capacity.
It's part of the DOE's promise to get rid of transportable classroom units within the next five years.
By only counting capacity in main school buildings, the change is meant to give a fairer representation of school overcrowding.
The change comes a few weeks after parents rallied against the trailers at a school in Washington Heights, claiming there were mold and mildew problems.
The trailers were put in place in the '90s as a temporary fix to overcrowding.
They were only meant to last about a decade.