Kaley Cuoco has officially filed for divorce.
The Big Bang Theory star – who has since removed her wedding ring – cited irreconcilable differences in court documents obtained by PEOPLE on Monday.
According to the filing, a prenuptial agreement was signed by the pair in November 2013, one month before their New Year's Eve wedding.
RELATED VIDEO: We Bet You've Never Seen Kaley Cuoco-Sweeting Interviewed by a Horse Before
Cuoco, 29, and Sweeting, 28, "mutually decided" to split after 21 months of marriage, her rep told PEOPLE exclusively on Friday.
The court documents also revealed that the actress and her tennis pro were separated as of Sept. 3.
Cuoco gave no signs of marital issues when she gushed about her estranged husband and his relationship with her ex and current co-star Johnny Galecki on Watch What Happens Live! on Sept. 20.
However, the couple had been hit with rumors of relationship trouble since April.
"The few times Kaley and Ryan were out together, the tension was noticeable," a source recently explained to PEOPLE. "You could tell the honeymoon phase had ended.
"They both seemed miserable."