French for teaching job in Quebec?

Hello friends!
I am an elementary school teacher in Toronto. I have valid teachers license for the job. Soon my family and I are moving to Quebec City, which means I will be resigning from my current job. I would like to find a teaching job in Quebec, once I move there. I have heard that most jobs in Quebec needs some sort of french language expertise. I have contacted an expert from a professional recruiter in Toronto and they also indicated about a similar criteria. I just want another confirmation if it is true. I know french a little and is ready to improve it. Should I take some sort of certification exam before trying for a job? If then, how long will it take? Any advice will be appreciated. Thanks!