Hilary Duff is making her split from husband Mike Comrie official.

Duff filed for divorce from the former hockey player a day after the Daily Mail reported that he enjoyed a "wild night out" in Beverly Hills last month. The timing is not coincidence, according to TMZ.

The couple of four and a half years announced their separation in January 2014, but Duff listed the time of separation as January 2013. She cited irreconcilable differences and asked for primary physical custody of their son Luca, who will turn three next month.

Duff wants Comrie to have visitation rights, but she's also concerned about how his partying habits will affect their son, sources told TMZ. The couple signed a prenuptial agreement, but the former Disney star only wants to keep her earnings and possessions.

At the time of their separation announce, Duff and Comrie agreed to co-parent Luca.

"They remain best friends and will continue to be in each other's lives," Duff's rep said in a statement to PEOPLE in January 2014. "They are dedicated to loving and parenting their amazing son, and ask for privacy at this time."