Kelis wants more milkshakes in her yard...or at least more money in her pocket.

TMZ reports that Kelis filed legal papers against her ex-husband Nas to cough up more money in child support. According to the gossip news site, Kelis is saying that the current ruling of $8,000 a month isn't enough to take care of their eight-year-old son, Knight.

The original order was put in place five years ago when their son was three. But now, that he's a bit older, Kelis is arguing that Knight has more needs and that those needs come at a cost. TMZ also claims that the paperwork argues that since Nas is a lot more well off now than he was a few years ago so he should be able to afford it.

Kelis didn't say how much more she wants, but she does want at least 50 percent of Knight's school-related costs, child care needs and unreimbursed health care fees.

This news comes a month after the two settled their custody battle allowing Nas "four full weekends over January, February and March" with their son. Previous to that, Nas' called his ex-wife "hostile" and voiced concern over not being able to see his son on a regular basis. It seemed the two were able to work it out until now.

The judge has yet to make a decision on Kelis' new demands.