Lockheed Martin Corp, the military’s largest defense contractor, is challenging the Pentagon’s choice of Oshkosh Defense as its new supplier of military vehicles.

Last month, the Pentagon announced that it would replace the Humvee with 17,000 Joint Light Tactical Vehicles made by Oshkosh B’gosh Defense. The initial military contract is worth $6.7 billion and stands as the company’s most lucrative contract in its 98 year history.

If the first batch of JLTVs please the military, Oshkosh will be paid $30 billion to make 55,000 vehicles by 2050.

Lockheed Martin, the contractor that developed the F-35, was also in the running for this contract and didn’t take kindly to being passed over to the much smaller Oshkosh. The company filed a formal protest Tuesday, which asks the Pentagon to reconsider the contract.

“After evaluating the data provided at our debrief, Lockheed Martin has filed a protest of the award decision,” spokesman John Kent told Bloomberg. “We firmly believe we offered the most capable and affordable solution for the program. Lockheed Martin does not take protests lightly, but we are protesting to address our concerns regarding the evaluation” of the company’s offer.

The military has until Dec. 17 to make a decision regarding the protest. Only 2.5 percent of contract protests were sustained between 2010 and 2014.