The 23-year-old former Millwall and Sheffield Wednesday defender signed a permanent deal with the Chairboys after impressing on trial in the summer of 2016, making his debut in the EFL Cup clash with Bristol City.
De Havilland regularly stood out in the Checkatrade Trophy and featured heavily in the second half of the 2016/17 season.
He moved out on a one-month loan deal to Aldershot Town in July 2017 to benefit from first-team football.
Wycombe boss Gareth Ainsworth told his club`s official website: “We have really strong competition for places throughout the team but particularly in defence, with a couple of players close to returning from injury, so there’s an opportunity for Will to go and get minutes under his belt at Maidstone.
“He did really well in the same division at Aldershot earlier in the season and we’ll keep a close eye on his progress to see how he’s getting on.”
The deal does include a recall clause.