BUFFALO, N.Y. (AP) — A Buffalo teachers’ union is calling on the public school system to create a potty training policy, arguing teachers are not contracted to change diapers.

The Buffalo Teachers Federation says teachers are too often stepping away from class to change diapers. WIVB-TV reports the union representing teacher’s aides, The Buffalo Education Support Team, is making a similar argument.

BTF President Phil Rumore says Buffalo public schools should create a policy where every student is toilet trained. The school district said in a statement that it is willing to continue a dialogue on the subject.

Under current state guidelines, children who are not toilet trained cannot be excluded from pre-K or kindergarten and districts cannot make it a condition of enrollment. Districts are allowed to work with families on toilet training.