Haylie Duff is engaged! The actress' boyfriend Matt Rosenberg popped the question on April Fool's Day -- but that ain't no joke.

"Matt just took me by total surprise and proposed…on April Fool's Day of all days! The moment was genuine and sweet (like him!) and I couldn't wait to say yes!" Duff gushed on her Real Girl's Kitchen blog. "We are so excited and happy to share our wonderful news with everyone! We both feel so blessed to have the love and support of our family and and friends and can't wait to start this new adventure!"

The happy couple took to Instagram to share some beyond adorable shots, including the above photo which Rosenberg captioned, "She said Yes!" With a picture like that, we can totally see just how in love the two are, with Rosenberg grinning into the camera and Duff smiling into her new fiancé's cheek. But that's not all the snapshot shows: we also get a clear look at Duff's unbelievable round sparkler, which is almost the entire width of her finger. That's a rock, right there!

Of course, Hilary Duff had to publicly congratulate her big sis and re-grammed her soon-to-be brother-in-law's photo, writing: "Love you guys so much!!!!" While this might be a difficult moment for the former 'Lizzie McGuire' star (who is going through her own separation from her husband Mike Comrie), we love how genuinely happy she is for her sister.

And of course Haylie had to share a snap herself (see below), which she captioned, "The future Mrs. Rosenberg! #Love." Congratulations to the happy couple!