The mother, who is the non-custodial parent, appeals from an upward modification of the child support provided by a previous agreement between the parties. We hold that (a) the record shows substantial increases, both in the needs of the children and the ability of the mother to pay, subsequent to the time of the obviously inadequate agreement, see § 61.14(1), Fla.Stat. (1989); Siegel v. Zimmerman, 319 So.2d 187 (Fla. 3d DCA 1975); Banks v. Graham, 252 So.2d 864 (Fla. 3d DCA 1971), and (b) in the absence of a showing that the guidelines were inappropriate in this particular case, see § 61.30(10), Fla.Stat. (1989), there was no error in applying the guidelines to determine the amount of the modification. See Huff v. Huff, 556 So.2d 537 (Fla. 4th DCA 1990); cf. Short v. Short, 577 So.2d 723 (Fla. 2d DCA 1991).

Affirmed.