The Ghanaian forward joined the Serbian giants two years ago but was farmed out on loan to FK Zlatibor Cajetina and Radnicki Mitrovica in the Prva Liga where he improved on his game.
His performances made him popular in the division while earning a place in the conversation for the best player in the league across the media landscape.
The 21-year-old was recalled by Red Star Belgrade last December after a breakout period with seven goals and three assists in 19 appearances for Radnicki Mitrovica
Mustapha's dream of becoming a member of Red Star first team has finally materialised after signing the extension this week.
Red Star Belgrade are second in the Serbian Superliga with 54 points after 21 matches. Five below their arch-rivals Partizan Belgrade.