A defective stretch of the Green Line near Packard’s Corner in Allston will be closed for 12 days in July in order for crews to fully replace the track, the MBTA announced Thursday.

Shuttle buses will replace Green Line trains between Kenmore and Boston College from July 17 through July 28, more than a week after the Sumner Tunnel’s summer-long closure, presenting even more challenges to Boston’s transit network.

The project on the Green Line’s B Branch already had been scheduled for this summer, but officials say they decided to accelerate the timeline after a trolley derailed near Packard’s Corner on June 17.

Roughly 30 passengers were aboard when the derailment occurred that afternoon before safely exiting the westbound train, without injury.

“The recent derailment is a stark reminder that we have work to do, and accelerating this work when schools are out is the best way to address a long-standing issue,” MBTA General Manager Phillip Eng said in a release. “This 12-day full access closure allows us to implement track renewal safely and most efficiently along the Green Line’s B Branch, and most importantly, improve service.”

More than 2,000 feet of track at Packard’s Corner and between Harvard Avenue and Allston Street will be replaced, “bringing this area into a state of good repair,” according to officials.

The upcoming work will include replacing duct banks and underground conduits, which provide power to trains, and repainting pedestrian crossings, bike lanes and platform edges along the B Branch.

Officials will discuss the project at an open house at Boston University’s Sleeper Auditorium next Wednesday at 6 p.m.

“We understand how frustrating service diversions can be,” MBTA Chief of Capital Transformation Angel Pena said in a release. “However, as a team, we will work as quickly and safely as possible to deliver these much-needed upgrades.”

This story is developing