Justice Minister Stephanie Vallee says the government will give France Charbonneau the seven month extension she was seeking.
The inquiry spent 30 months looking at the construction industry and its ties to organized crime and political parties and heard from its final witness last November.
The commission was created in late 2011 and began hearing from witnesses in the summer of 2012.
The original deadline for Charbonneau's report was October 2013, but the former Parti Quebecois government extended it by 18 months in early in 2013 until April 2015.
Vallee says the report is now due by Nov. 30.