"We're filming more within our homes, and he is right there with us," the star tells PEOPLE

When Keeping Up with the Kardashians returns in September, we'll be seeing more of Rob Kardashian.

Khloé Kardashian says her brother, who has slowly reemerged into the public eye in recent months, is turning over a new leaf.

"Rob is going to be on the show more," Khloé, 36, tells PEOPLE while discussing her migraine-related Take Back Today campaign with with Nurtec.

Over the years, Rob, 33, has struggled with weight gain and depression, retreating almost entirely from the spotlight. But he's been popping up in more and more recent photos with his famous family, and Khloé says while fans may not always see him, he's "always around."

"Rob is truly my best friend," she says. "I love, love, love, him. He's always around. People think we don't see him, but just because the public doesn't see him, doesn't mean we don't see him."

"We never push him, everything is his free will," she continues. "We always take photos — we have so many memories, but nothing public, so I was really happy because on my birthday, he said, 'Oh, you can post that. I'm fine, I feel good.' It made us feel so good that he was comfortable. And the reaction from the public was so positive that it gave him a boost of confidence."

"So now he is filming more," she adds. "We're filming more within our homes, and he is right there with us. I'm excited for everyone to see that. He's such a good person and I'm just happy he's coming back around on camera a little bit more."

Kardashians birthday party
From left: Rob Kardashian, Khloé Kardashian, Kendall Jenner, Kylie Jenner
Rob Kardashian Instagram
Credit: Rob Kardashian Instagram

A source told PEOPLE last month that Rob is "doing well."

"He takes care of himself, works out and eats better," said the source. "He knows he looks better. And he is comfortable enough to be photographed. He wants people to know that he is doing well."

One person who won't be as much of a part of the second half of season 18? The eldest Kardashian sister, Kourtney, 41, who announced last fall that she had taken a step back from KUWTK to focus on her family.

"She's out of most of it," Khloé tells PEOPLE. "Kim and Kourt go to Paris for Kanye [West]'s fashion show, so she's in a little bit, but she's really taken a break the rest of the season."

As for how the family has been filming in Los Angeles amid the coronavirus pandemic?

"It's a lot of self-shooting," Khloé says. "Because the pandemic started and we had to document it."

The star also opened up about life under lockdown during an interview on SiriusXM's The Morning Mash Up with Nicole Ryan, Ryan Sampson and Stanley T.

"It's a lot of us filming but in our individual homes, on tripods where you just set up and go," she explained. "Now, that's kind of everyone's normal, but during it, we're like, 'How un-motivating!' Like, it's just me or True in a room, and it was very different and awkward."

"We're so used to being in each other's faces, so it's different," she continued. "But maybe that's good for viewers to see that difference, and maybe it's good for people to see that we can survive without each other!"

Season 18 of Keeping Up with the Kardashians returns this September on E!