While harassment and more egregious workplace behaviors finally received the attention they deserve thanks to the #MeToo movement last year, another crucial issue plaguing the office continues to go unnoticed.

Bullying in the workplace is turning out to be a bigger concern than many would think. Without clear legal or office policies, oftentimes workers aren’t even sure what constitutes bullying, or if they should report it. And when they did feel bullied, 58% of workers did not even report it, which means it’s likely happening right under HR’s nose (and could be driving your best talent away).

With two-thirds of workers claiming they’d actively pursue a new job if bullied — and nearly half saying they’d leave without another job lined up — it’s evident that employees today won’t stand for it. That means human capital and other valuable resources will all be gone. Don’t uncover the truth about a toxic office culture from an exit interview. Instead, stamp out bullying at your company with this three-step process: define, educate and address.

Who are the bullies?

From peer pressure to shaming to shouting, it can be difficult for workers to assess what bullying in the workplace actually looks like. Unlike the schoolyard, office bullies tend to be less overt or physically harmful, and more physiological and subtle in nature, which makes it tough for employees to know whether or not they should report incidents. And it’s just as likely to come from jealous peers as it would from insecure managers.

In order to outline these boundaries, it’s HR’s responsibility to define workplace bullying. According to the experts at the Workplace Bullying Institute, it’s described as “repeated, health-harming mistreatment of one or more persons (the targets) by one or more perpetrators. It is abusive conduct that is threatening, humiliating, or intimidating; work interference; or verbal abuse.”

Bullies tend to use the rules of the organization to their advantage, which means that starting with the policies is key. Whether there are laws around certain types of bullying or not, you need to make it clear in the employee handbook and company values that as an organization, you will not stand for, or tolerate, toxic behavior.

It’s important that the message starts with senior leadership and filters down throughout the company. Use the word harassment instead of bullying, so the implications are unmistakable. It should be clear that it is harassment, whether the behavior is gender-related or not.

Train employees

As HR professionals, it’s our job to make employees feel comfortable reporting anything that is not creating a safe work environment. So, once you’ve demonstrated a clear anti-bullying stance through your company policies, the next step is to educate workers about how to handle it.

That means you need to have multiple channels for workers to bring instances of bullying to light and trust that those channels won’t break confidentiality. This can include everything from creating anonymous avenues for reporting inappropriate behavior, to holding bystander intervention training sessions.

Address it with actual punishment

Ultimately, workers have to feel there will be repercussions for bullies, or they will not feel comfortable bringing the issues forward. If you do not actually address it, then HR is playing right into the hands of the bullies and becoming complicit in creating a toxic office culture. This can even cause workers to feel that they should side with the bully, or avoid speaking out to stay off their radar.

Employees may not always see the consequences directly, after all, the bully’s privacy is also important. However, employees should feel that their reports are taken seriously. Punishment should be decisive – make it clear the company will not stand for this behavior. Work with the bully to unearth the cause of the harassment, and channel their competitive or negative energy into something productive. If they’re unable or unwilling to change their ways, they’ll have to go.

Don’t let office bullying happen under your nose. By getting proactive with clearly defined anti-bullying policies, and educating workers on how to deal with these situations, you can likely nip recurring instances of harassment in the bud. That means a happier, healthier work environment that will keep great talent around for years to come.