A society of American historians has announced it will not be accepting panels at its upcoming conference if those panels don’t include women or racial minorities.

The Society of Historians of the Early American Republic (SHEAR) is open to all historians who study the period between America’s independence and the Civil War. The group hosts an annual conference which features dozens of panels on different topics, and now it wants participants to know that panels which lack diversity aren’t welcome.

In a guide for prospective panels published Tuesday, SHEAR says the key to having a prospective panel accepted for next year’s conference in Philadelphia is ensuring that it isn’t all white men.

“Display diversity in your selection of personnel,” the guide warns (emphasis theirs). “It is no longer acceptable to submit a panel that’s all-male and all-white … The best panels have a mix of presenters—by gender, graduate students and professors of different ranks, racial diversity, people from a range of universities, non-academic presenters, people who haven’t appeared on a SHEAR program before or in a while, people who don’t all live within the city limits of one university town.”