Duff announced the news Thursday on Instagram, showing off her ring in two sweet selfies of the couple.
“He asked me to be his wife,” she captioned the post.
Koma posted the same photos, writing: “I asked my best friend to marry me… @hilaryduff.”
The Younger actress was first linked to Koma, a singer/songwriter, in early 2017. They broke things off a few months later in March, but by September, Duff had started dropping hints that she and Koma, 31, were back together, sharing Polaroids of herself strumming a guitar and blowing out the candles on her birthday cake.
The couple soon reunited for good, and they’ve been going strong ever since.
In June 2018, Duff, 31, announced she and Koma were expecting.
“Guess what guys! @matthewkoma and I made a little princess of our own and we couldn’t be more excited!!!!!” she captioned a photo of him sweetly kissing her cheek as she showed off her growing baby bump.