I manage a group of about 13 people, and we communicate via instant messages. Employees are aware management has access to chats, which is a condition of using the feature. I have one employee who persistently bad-mouthed me in online conversations. I confirmed that he was aware that I could see his messages, and I told him I saw messages that concerned me. He told me he felt I fought harder for someone else to be promoted over him. I explained that I had advocated for him but that upper management had denied the promotion. Since then, he’s disengaged from his job and is only doing the bare minimum. I feel I should address this with him, but I’m unsure of how to do so.

This is a difficult and surprisingly common situation. Employees who feel they are being treated unfairly often react in this manner. Your employee is taking it out on you in a passive-aggressive way. Rather than confronting you directly, he wrote messages he knew you would see, probably counting on you being too nice to impose consequences for his actions.

It wasn’t a bad guess on his part. Managers don’t like confrontation any more than the rest of us, so often they ignore this type of behavior until it reaches a breaking point.

First of all, you’ve done the right thing by bringing it to his attention. It puts him on notice that you won’t stand for his little snipes. The validity of his complaint is irrelevant to how you handle this. Sometimes we, as managers, get caught up in defending ourselves rather than dealing with the problem.

And what is the problem? You have a disengaged employee who is behaving inappropriately and influencing his co-workers. (Because, of course, the IMs are being sent to someone else within the office.) How do you deal with it? Five steps:

1. Make the employee aware that you are aware of the problem. You’ve already done this, so good job. He knows that you’re monitoring his communications and that you see his inappropriate behavior.

2. Make it clear the behavior has to stop. He cannot continue to send snarky IMs to his coworkers, period. No more discussion needed. The behavior is distinctly different from the attitude, although that comes next.

3. Have an attitude discussion. Your employee may be justified in his opinion that he’s been treated unfairly. However, often this behavior is indicative of why the person hasn’t received the raise, promotion or recognition that they demand. Whoever made the decision did so because they knew the person had issues, and passive-aggressive behavior is an issue. Make it clear that, regardless of salary or title, your employee needs to do his job well and enthusiastically. He needs to be engaged. “Fake it till you make it” is fine in this situation.

4. Clearly document the requirements. Depending on the seriousness of the  misbehavior, this may be a simple email: “John, thanks for our chat today. This email is to confirm that 1) you will not send any more negative messages or emails about work, and 2) you will focus on doing your job and doing it well. I am happy to help out when you need assistance or guidance.” If it’s a serious problem, you can place the employee on a formal performance improvement plan. These PIPs are usually 60- to 90-day plans with clear goals and markers that the employee must reach or face termination.

5. Follow up. This step is absolutely critical. You can’t just say “stop” and then expect it will stop without follow-up. You’ll need to give consistent feedback, or you won’t see success. If being negative has become a habit, it might take some time to cure him. And, after going through this, you might find out that he is not going to change and he’s never going to be engaged. In this case, think about encouraging him to look for a new job.

If worse comes to worst, you may have to terminate him, but most likely he’ll either turn it around or leave on his own. Managing people is a challenge. Facing that challenge head-on is most likely to bring success and happiness.