But at the biggest U.S. financial firm, Dimon is growing increasingly frustrated with the number of employees viewing meetings not as a time to 100% focus on the topic at hand—but to multitask. 

“I see people in meetings all the time who are getting notifications and personal texts or who are reading emails,” Dimon wrote in his annual letter to shareholders. “This has to stop. It’s disrespectful. It wastes time.” 

And while his words may sound blunt, meetings can take up half of workers’ entire work week, and more often than not, they’re completely ineffective.

It’s why workplace leadership experts told Fortune that Dimon addressing the elephant in the room is a welcome sign.

Dimon is not a fan of unproductive meetings—and he’s not alone

“Dimon’s bluntness is refreshing,” Melody Wilding, an executive coach, told Fortune. “Finally, someone with power calling out what we all see happening. The core issue here is respect for everyone’s time though, not the tech itself.”

Addressing workplace productivity has been a top priority in recent weeks for Dimon, who notably called JPMorgan Chase’s 313,000 staff back into the office five days a week. While multitasking during a remote meeting can be easy to get away with, doing so in person is a disrespectful and bad habit, said Gary Rich, founder of executive coaching firm Rich Leadership.

“Are manners ‘old fashioned?’ Is listening to what’s happening in a meeting ‘old school?’” Rich said to Fortune. “When people are multitasking during a meeting, the distraction creates a ripple effect—the speaker feels disrespected, other attendees lose motivation, and the meeting becomes less productive.”

While workers may be tempted to incessantly check their emails or text messages for work or personal purposes, executives across industries are tightening their grips on meeting protocol to max out productivity from their teams.

At Amazon, PowerPoint is banned. Instead, Jeff Bezos expects all get-togethers to include a six-page preparation document. Meanwhile, Vimeo’s Philip Moyer starts every meeting with a customer story; Block’s Jack Dorsey bans meetings on Tuesdays; And Nvidia’s Jensen Huang has no one-on-one meetings at all. 

But overall, executive leadership experts told Fortune that meetings, especially in-person ones, are the best opportunity to show sincerity and dedication. 

Read more from Fortune

Those who take Dimon’s words to heart—and prioritize being present instead of checking messages—may have better success at catching the attention of leaders who could fast-track a promotion.

“Being a leader means establishing norms that are in the best interest of the company—and focused, productive meetings shouldn’t be too much to ask,” Rich said.

Jamie Dimon’s tips for how to have a productive meeting

Dimon doesn’t just want to ban cell phone use, he has a laundry list of grievances and steps for improvement when it comes to meetings.

In the first instance, only absolutely necessary meetings should be scheduled, Dimon said, and all the participants should come prepared to bring their best ideas to the table before, during, and after. 

He added he “always” does the pre-read and gives it “100%” of his attention.

“Here’s another example of what slows us down: meetings. Kill meetings. But when they do happen, they have to start on time and end on time—and someone’s got to lead them. There should also be a purpose to every meeting and always a follow-up list,” Dimon wrote.

Moreover, workers must be comfortable being fully transparent with their colleagues.

“One annoying example of bureaucracy is the meeting after the meeting, where an executive tells me what they didn’t want to say in front of their partners. That’s not acceptable. Don’t bother. I’m not their messenger. Lay it on the table in real time. Shine light on a problem or disagreement. Be transparent with your colleagues,” Dimon said.