My first real job out of college was at a startup nutrition company where we all wore many hats. (i.e. about six of us ran the entire place). Vacation days were offered — about three weeks per year, but we weren’t necessarily encouraged to use them. In fact, my boss often got a little passive-aggressive when I talked about taking time off, so I would always reassure him, “But I’ll be available! Our hotel has Wi-Fi! If you need anything just call me!”

And call me on vacation he did. All the time. He even paid for my roaming charges and the plane Wi-Fi so I could work while in the air.

It turns out, my experience wasn’t that unique. According to a survey by Project Time Off, a lot of Americans aren’t just failing to check out on vacation — a majority them are not taking the full amount of time off they’ve earned.

The survey showed that 55% of American workers did not use all of their vacation time in 2015, leaving 658 million days unused. Of these, 222 million of them were lost, unable to be rolled over to the next calendar year. Project Time Off calls this “America’s Lost Week.” An entire week of potential time away from work that Americans are choosing not to take. And their survey found that managers are staggeringly to blame.

37% of survey participants say they didn’t take vacation because of a fear of returning to a mountain of work. 22% say they want to show dedication to their job and 28% blame their position at the company, saying the higher you get up the harder it is to take vacation. But 50% reported a lack of support from their boss, and 80% of employees said that if they felt fully supported and encouraged by their boss, they would be likely to take more time off.

At my next job, I worked for a manager who not only encouraged me to take my hard-won vacation days, but actually lectured me when I promised him I’d check in with him while out. “Come back refreshed and ready to work,” he told me. “I don’t want your vacation work. Vacation work is bad work. Come back in love with your job again.”

So I did just that. I took off to Thailand for ten days and you know what? I didn’t come back lazier, with dreams of Pad Thai and elephants swarming my head. I came back curious about what I missed. Hungry to make things happen. Happy to see my friends at work. And the building didn’t burn down like I thought it might.

If you’re a manager or boss at any level, you can’t afford to not let your employees take vacation. Real vacation, not phone-checking, email-shooting vacation. And here are three things you can do to encourage them to actually do it.

Lead by Example

A startling 65% of bosses said they don’t check out on vacation, so is it any wonder that employees aren’t? Hands down, the best thing you can do for your employees to get them to actually “vacation” on vacation, is to do it yourself. Take a week off. Don’t check in with them. Ignore your phone. Come back refreshed. If they see you do it, they’ll be more likely to think that they can too.

My second manager was the master at this. Not only did he take all of his vacation days and ignore any and all fires sent to him during that time, but he proudly departed work at 5:00 on the dot. “The work is never done,” he would say while we all sat at our desks, waiting for an appropriate time to slip out, none of us wanting to be the first. “You’re done at 5. Go home guys.”

According to a survey by the U.S. Travel Association, 17 percent of managers considered employees who use their vacation days to be less dedicated. My manager proved this was not the case, being the first to stand up and admit he had a life outside of work.

And if you’re still on the fence, Rebecca Newton, a contributor at Forbes, actually says that checking out as a manager can be a great way to assess the strength of your team. She says, “ A vacation can be a great test to see whether our team is as strong as it can be, operating without us. And if the world, or a small part of it, does fall over while we’re not there, it’s a good sign of where we should focus before our next vacation.”

Plan Ahead

If possible, sit down with your employees multiple times a year and ask them to schedule vacation time. A great time to do this is a few months before summer begins, or before the holiday season. To make it easy, you could even do it every quarter.

Doing this achieves two purposes: (1) It ensures that employees actually take their vacation days allotted, and (2) It allows you to plan ahead as a manager, so you can schedule around busy times, launches and conferences, as well as plan around popular vacation request times such as Thanksgiving, Christmas, and Independence Day.

By planning ahead, you can make sure the employee knows that you were already planning on them being off during that period, giving them more peace of mind to actually check out.

Jeff DiPiro, a Business Performance Advisor at Insperity also suggests you meet with employees individually to create a game plan for them to check out during their vacation time. He says, “Many employees feel guilty for burdening their team-mates with extra work. If an employee comes to you trying to back out of vacation, or announces that they’ll be working during vacation, it’s time to coach them through the steps of vacation planning.”

He then suggests that you help them defer tasks, cross-train other employees who can take over while that employee is out, and communicate vacation dates to the team, indicating who their backup will be. By doing so, he says that employees will feel more secure in checking out during vacation, instead of feeling that their job will crumble in their absence.

Though I didn’t realize at the time, my second manager was doing this on a regular basis. A few of us traveled regularly, attending trade shows. He assigned each of us on the traveling team a “second” who covered emergencies for us, performed essential job functions, and supported us on the road. Creating a “second” not only encourages employees to check out for vacation, but also protects the company should an individual leave their job. A “second” who understands that individual’s job function and daily tasks makes the transition to a new hire much smoother.

Make Your Employee Feel Valued

Sharon Danzger, a Productivity Consultant, says, “As our economy has shifted from factory workers to knowledge workers, there is an underlying fear that if we do not make ourselves indispensable, we might be replaced. If everything goes smoothly in the office while we are away for two weeks, maybe the firm does not really value my contribution. Will I be the next casualty in a round of layoffs?”

Employees who do not check out during vacation, or worse – don’t take vacation days at all, may feel that way because they are worried about their job being there when they return. By making them feel valued on a regular basis, they’ll be more likely to actually check out during vacation time.

Upon my return from ten days in Thailand, my manager (the second one) called me into his office. After so many days away I was nervous, feeling that something may have changed in my job, that they found I was not as valuable as I imagined, that I was being demoted. But instead of any of those scenarios, he asked me, “So? How was it?”

I spent the next ten minutes reliving my favorite experiences, grateful to work for a company and an individual who cared about my personal happiness and growth. I returned to my desk recharged and ready to commit to a company that was invested in me.