Kanye West donated $1 million (£765,900) to charity in Kim Kardashian’s name to celebrate her birthday on Monday.

The reality star took to Twitter to reveal her husband’s sweet gesture, sharing a snap of the “certificate of donation” which stated that Kanye and the pair’s four children, North, six, Saint, three, Chicago, 19 months, and Psalm, five months, had donated $1 million to four charities dedicated to criminal justice reform – a cause Kim has been concentrating on while studying to become a lawyer.

Alongside the picture of the certificate, Kim wrote:

“I got amazing gifts from my whole family and Kanye (gave) me the most amazing bags. But he also donated $1 million to my favourite charities that work so hard on prison reform on my behalf from him and the kids. This makes my heart so happy!”

The four charities are Cut 50, Buried Alive Project, Equal Justice Initiative, and the Anti-Recidivism Coalition. Following the donation, Cut 50 – a national initiative to reduce the prison population while making communities safer – took to Twitter to write:

“@KimKardashian, thank you from the entire team (and happy birthday!) These funds will help fuel our efforts to use humanisation & legislation to transform the U.S justice system. We’re proud to be in this fight with you and honoured to have you part of our #cut50 family!”

Kim’s sisters also sent her messages on her big day, with Kylie Jenner writing:

“Happy birthday to my beautiful big sister. I’m so blessed to have you in my life!! Your love, guidance, selflessness and loyalty are unmatched. i love you in this life and beyond!!! @KimKardashian.”