Retroactively applying amended Welfare and Institutions Code section 731, subdivision (a)(4) to commit appellant to the Division of Juvenile Facilities (DJF) did not violate ex post facto principles. Appellant was declared a ward of the court and granted probation in 2009 after he admitted two counts of continuous sexual abuse of a child (Pen. Code, § 288.5). From 2009 to November 2012, he was placed in two residential juvenile sex offenders treatment programs and his adjustment was poor, with multiple probation violations. The juvenile court sustained the district attorney’s supplemental petition seeking continued jurisdiction over appellant and a modification of placement, and committed appellant to DJF. On appeal, appellant contended that the commitment amounted to an ex post facto law because DJF was not an authorized placement when he committed his offenses. (See In re C.H. (2011) 53 Cal.4th 94.) Held: Affirmed. In 2012, the Legislature amended section 731, subdivision (a)(4) in response to C.H. to clarify that a DJF commitment was authorized for a ward who committed any sex offense listed in Penal Code section 290.008, including section 288.5. By committing appellant to DJF, the juvenile court retroactively applied this amendment. However, this did not violate ex post facto principles because a DJF commitment does not constitute greater punishment than the local commitments that were available when appellant committed the offenses. Although a DJF commitment is more restrictive, it does not increase the time a ward must spend in custody. The requirement that a juvenile committed to DJF for a sex offense listed in section 290.008 must register as a sex offender is not greater punishment because sex offender registration is a civil regulatory scheme. While a ward committed to DJF may be detained past the age of 21 or 25 under Welfare and Institutions Code section 1800 et seq., this procedure is civil in nature and akin to civil commitment procedures in adult court, to which ex post facto principles do not apply.