Imposition of additional terms does not violate double jeopardy: The prohibition against double jeopardy generally precludes the court from imposing a greater sentence on remand following an appeal. ( People v. Price (1986) 184 Cal. App. 3d 1405, 1408, 229 Cal. Rptr. 550). However, there is an exception to the rule "when a trial court pronounces an unauthorized sentence. Such a sentence is subject to being set aside judicially and it is no bar to the imposition of a proper judgment thereafter, even though it is more severe than the original unauthorized pronouncement." (People v. Serrato (1973) 9 Cal. 3d 753, 764, 109 Cal. Rptr. 65, 512 P.2d 289, fn. omitted, disapproved on another point in People v. Fosselman (1983) 33 Cal. 3d 572, 583, fn. 1, 659 P.2d 1144, 189 Cal. Rptr. 855). A sentence is unauthorized where the court violates mandatory provisions governing the length of confinement. ( People v. Scott (1994) 9 Cal. 4th 331, 354, 885 P.2d 1040). The sentence in this case was unauthorized. Section 667.61, subdivision (g) requires that additional terms "shall be imposed." (See, e.g., People v. Lockwood (1998) 66 Cal. App. 4th 222, 227). Therefore, as the Serrato court explained, "a defendant who successfully attacks a judgment which is in excess of the court's jurisdiction is not necessarily entitled to claim the protection of that invalid judgment as an absolute limitation upon what the court may do thereafter. " (People v. Serrato, supra, 9 Cal. 3d at p. 765).