Nothing can erode your credibility more quickly than being labeled as a person who makes disparaging comments about your boss, peers, or customers. This type of behavior is a classic career derailer that can prevent people from achieving their full potential or, worse, result in them getting demoted or fired. If you’re reading this and are “guilty as charged,” make a commitment to take immediate, corrective action by ceasing and desisting this harmful habit. Vow to avoid this behavior and build a solid reputation to help bolster your success.

But if the problem of bad-mouthing isn’t your own, but perhaps the plight of some disgruntled co-worker or direct report, it’s also important to know how to handle it effectively. Here are three ways:

Don’t get sucked in from the start. Talking bad about others is toxic and infectious. It can start with one person, then spread to many just like a flu. Wash your hands of the behavior by avoiding it altogether or chart out, or devise in advance, smart tactics for changing the communication course. This will send the message that you’re not interested in this idle, self-defeating chatter.

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Give the bad-mouther some much-needed feedback. Bad-mouthers aren’t always bad people — they sometimes just pick up bad habits. Explaining this to someone through frank feedback can help. Be candid and let the person know that they are developing a reputation as a negative individual. Share your concerns on how the negativity is affecting you and the people around this person. Tell them that this type of behavior could have a negative impact on their career. It takes courage to pull this off but straight forward, assertive feedback is the answer in this situation.

Reinforce the positive change. When you notice a change in someone, particularly some genuine efforts to stop a self-destructive habit, tell that person! You don’t have to say something as overt as, “You’re doing a good job not slamming Mr. Reynolds this week,” but something like, “You’ve been doing a great job with being more positive and talking about the right things,” does the trick. This not only praises the person (who well deserves it), but also sends a gentle reminder that you’ve not forgotten about his or her challenges with bad-mouthing. You are still paying attention to this person’s behaviors and communication!

What are some other suggestions when it comes to alerting a co-worker about his or her bad-mouthing habit?