The 24-year-old midfielder has spent this season on loan at Chievo from French side Chateauroux.
Constant said: “I am very happy. This was my first experience in Italy and it was a very positive one.
“I found a great group of players who welcomed me immediately and a club that made me feel important.
“I am pleased to have given my contribution to keep Chievo in Serie A. A heartfelt thank you to everyone.”
