Shortly after acquiring the property, the museum underwent a two-year renovation beginning in 1989.[1] The renovations led to the creation of four exhibition galleries within the pavilion,[10] and a section of preserved jail cells to highlight the building's former use as a prison.[2] Designs for the renovation were by Charles Dorval and Louis Fortin.[8] Along with the building, Dorval and Fortin also designed the underground access that connected the Gérard Morisset pavilion with the Charles Baillairgé pavilion.[8] In an effort to maintain the Battlefield Park, the design concealed a section of the new wing under the park's natural landscaping.[8] The museum opened the pavilion to the public in May 1991.[3]