Leaders play a significant role in setting the tone of the workplace. It is hard to have a harmonious and trusting environment without good leadership. Likewise, a fractious and backbiting team reflects behaviors that leadership has promoted, or at least has allowed to persist.

If you find yourself leading a toxic team—whether you have been in your role a long time or are just taking over—you have to diagnose the problem and work to improve the culture. Here are three common problems that are often lurking behind teams that cannot get along:

ARE THE RIGHT PEOPLE IN THE RIGHT SEATS?

Lots of books on leadership throw around the word trust and talk about how teams that do not trust each other perform badly. Unfortunately, trust just means that you believe that the people around you will follow through on their commitments. So, there isn’t really a single thing you can do to create trust among team members.

One thing you can do, though, is to start by ensuring that the people on your team are competent to do their jobs and that they are being given roles that enable them to use their abilities. On many toxic teams, you have at least a few folks who are not that good at their jobs. It takes a lot of work to identify these poor performers and to create a plan for them to either improve their skills or to move them to different roles or out of the organization altogether. As a result, they stay in their jobs and continue to gum up the works.

You have to start by taking a close look at the performance of team members. Are they doing good work? Do they complete the tasks they are given in a timely fashion? If not, it is time to sit down with those individuals and set clear expectations about what they need to accomplish. If that requires additional training or mentoring, you need to set that up, as well. You have to be willing to give people an honest assessment of their abilities and then hold them accountable for improving.

It also means that you may need to shift some people’s roles around. For example, people are often given roles as a supervisor because of their skill as an individual contributor. But, just because someone was good at sales, financial analysis, or customer service doesn’t mean that they are going to be effective at supervising others. Start by finding them a mentor to work with them to improve their skills. However, you may discover that someone has been put in a role that is not a good fit to their abilities (and they don’t seem to be growing into the role), and so reorienting their responsibilities will enable them to shine.

You are likely to find that as you start putting the right people in the right seats, that trust among team members improves.

HAVE YOU GOT SOME BAD APPLES?

Of course, not everyone is a team player. The more people who work for you, the more likely it is that you will end up with someone on the team who does not have everyone else’s best interests at heart.

You need to listen to what people are saying about their colleagues. If there is someone who is always taking credit for successes and blaming others for errors and failures, you might just have a narcissist on your team. These individuals often seem like gifts at first, because they show off their accomplishments. But, they sap everyone else’s motivation over time, because they do not acknowledge the efforts of their peers, but instead work to burnish their own image. You need to work with the narcissists to help them see the value of playing well with others (and work to move them off the team if they do not take your counsel to heart).

You may also have people who are mean in other ways. They may have prejudices that they reveal in their interactions with others. They may engage in other inappropriate behavior like sexual harassment or yelling at colleagues. When you witness or hear about negative interactions caused by bad behavior, you need to address it quickly.