Beware of the slack attack.

Lil Wayne allegedly bailed on last weekend’s Panorama music festival in New York because “he didn’t want to do it,” an insider told Page Six. “This was going on for days, like three days. He just did not want to do the festival.” Another source claimed Weezy had “hated” New York since his 2007 arrest on a gun possession charge, for which he spent an eight-month jail stint on Rikers Island.

The rapper, for his part, blamed his absence from the three-day festival on a weather-related flight delay. And his attorney Ron Sweeney threw cold water on the report: “All incorrect. I was there at the festival. We wanted to do the show. We had a flight delay. We tried to switch with Gucci Mane and go on at 8:30 p.m.,” he told Page Six. “Why would someone turn hundreds of thousands of dollars down in a city where he just did Summer Jam?”

Either way, nearly everyone (93%) has a coworker who doesn’t do their fair share, according to a 2013 VitalSmarts survey of 549 people — and four in five say their work quality diminishes when they have to cover colleagues’ work. Yet just 10% of people speak up about coworkers’ slacking, per the survey; top reasons include the belief that voicing concern won’t make a difference, an unwillingness to undermine a working relationship, a feeling that it’s not their place, fear of retaliation, or uncertainty over how to broach the conversation. Meanwhile, research suggests that low performers are actually more engaged at their jobs and often don’t even realize they’re underperforming.

Also read: What to do when you find out a co-worker makes more money than you

HR consultant Susan LaMotte, CEO of the employer brand experience firm Exaqueo, charts out several common workplace “slacker personalities”: There’s the “ego slacker” who’s too good to work, the “apologetic slacker” who’s constantly missing deadlines but always sorry, the “silent slacker” who seems totally on board in the beginning but then disappears, and the “lazy slacker” who just doesn’t want to do the work and thinks they can get away with it, she suggested.

If you work with one of these people, here’s advice from LaMotte and other experts on how to handle them:

Figure out where the person is coming from. Don’t fall prey to “fundamental attribution error,” said workplace psychologist Christine Allen, or the tendency to overemphasize others’ personal characteristics while downplaying external factors. For example, you might think someone is a jerk for cutting you off on the highway — but when you do the same to someone else, it’s because you were late to work. “Start with the premise that ‘Hmm, maybe there’s a good reason why they’re doing this,’” Allen told Moneyish. “Contextualize it. Try to understand what’s going on.” Ask yourself if this is a motivation problem or an ability problem, Dewett added.

Decide whether their slacking actually affects you, said leadership expert Todd Dewett. “Sometimes the do-nothing option is the smartest, because we do have to choose our battles,” he told Moneyish. “If their work is meaningfully interdependent with yours and their performance issue is making your work more difficult or impossible,” or it’s affecting morale, Dewett said, you might want to act.

Also read: Why you should suck it up and ask your coworkers for help

Don’t rush straight to your boss. You may first approach the slacker in question to ask why things seem off lately, Dewett said. Cite specific examples and be positive, respectful and private. “You’re kind, and you’re brief, and then you shut up and let them respond,” he said. A group effort of the same variety may also help, he added — but if you get a non-response or negative response, you’ve done your part and can raise the issue with your manager. “Every one of these steps you should’ve documented with dates and times, people involved (and) conversations had, so you can give that to the boss,” Dewett said.

“I would be clear, unemotional and direct (with the slacker),” LaMotte added. “Reference specific examples, what you need now and why you need it, and your next steps if action is not taken.”

Resist the temptation to do their work for them, LaMotte said. “The second you do it for them, the lazy slacker wins,” she said. “You just have to (resist). … You care about the work and your project; you don’t want it to turn out badly. And that’s usually what drives type-A people or high achievers to do the work of lazy people.” If you do decide to cover their share in order to turn in a top-notch product, Allen said, then make sure you reflect the experience for next time: What did you learn, what could you have handled differently, and should you have confronted the person or talked to your boss sooner?

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And resist the urge to start slacking yourself. Chronic underperformers can affect the morale and productivity of those around them, Allen said. “The people around them are much more likely to do less work, to copy those behaviors … We’re wired to be concerned about fairness,” she said. “So we will lower our own standards … so that it doesn’t feel unfair that this person is getting away with doing less, even when it’s not in our best interest.”

Be proactive about who you work with, if possible. Before your boss even assigns a new project, express interest and name a team member you think will help you deliver results, LaMotte said. If you get assigned to work with the slacker, you might convey concern along with specific examples and either a) ask to work with someone else or b) say that while you’ll do everything you can to set deadlines in advance, you want to ensure that this person’s potential poor performance doesn’t reflect poorly on you — or, more importantly, the project’s end result.

Don’t stew in resentment — take action. “Instead of just being frustrated and disappointed, take action and do everything you can to set yourself up for success and set that person up for accountability,” LaMotte said. That means creating documentation, she said. On any project, LaMotte added, be clear about each person’s responsibilities from the start and make sure everyone signs off in writing.