Saint-Maximin arrived on Tyneside last summer from French giants Nice for a fee in the region of £16m.
The Frenchman initially put pen to paper on a six-year deal at St. James’ Park, but is now poised to receive a new contract with the Magpies.
Magpies boss Steve Bruce is impressed with how Saint-Maximin has evolved since arriving at Newcastle and the winger has caught the eye with his performances.
Bruce wants to make sure Saint-Maximin is locked down and the club have moved to do so.
Newcastle have put a six-year contract in front of the winger and he is set to sign it.
Saint-Maximin has the belief that his performances mean he should be earning more money at Newcastle and the Magpies are taking steps to please him.
The Frenchman’s debut Premier League season saw him registering 26 appearances for Newcastle but the winger missed 11 league games through injury.
But Saint-Maximin has started all but one of Newcastle’s league games this season and starred against Burnley in the Magpies 3-1 win with a goal and an assist in his last top flight outing.