Motherwell manager Graham Alexander said the club was delighted to see Mugabi extend his stay.
“We’re delighted Bevis has agreed to extend his stay with us at Motherwell,” Alexander told the same portal. “We’ve been really impressed with his contribution since January, both on and off the pitch.
“We can also see the potential for him to get better and continue to help the team achieve future success.”
Mugabi, who has been capped 10 times by Uganda, has been a key figure at the heart of the defence for Motherwell in the 2020/21 campaign, although injury has restricted his outings of late.