The Belgian took over at the Stade du Hainaut in October and has since guided Valenciennes to within touching distance of moving out of the bottom three.
Valenciennes are 18th in Ligue 1, but could pull out of the relegation zone with a victory over second-bottom Sochaux on Saturday.
Jacobs has enjoyed a long career in coaching, winning league titles with Belgian side Anderlecht and Danish outfit Copenhagen.
The 60-year-old intends to stay with Valenciennes next season regardless of whether they avoid the drop, but revealed that he will retire when his time with the club comes to an end.
"This will certainly be an endpoint on a professional level," Jacobs said. "But I am even more motivated.
"This can be a very beautiful last mission. I am willing to give it all of my energy."
