Congratulations to Aly Michalka -- she's engaged to boyfriend Stephen Ringer!

The 25-year-old actress-singer made the exciting announcement by way of Instagram, first posting a picture of her and her sister (and Aly & AJ/78Violet bandmate) AJ, captioning the photo, "Hmmm... no one's noticed yet! #Lookcloser," before going all out and posting a close-up shot of her new bling -- revealing one gorgeous, square-cut sparkler.

"So this happened.....7/8," she captioned the second pic, complete with engagement ring and happy couple emojis. The photo shows off Michalka's princess-cut diamond and gorgeously thick band. (We also have to point out how much we love her half-moon mani.)

The 'Easy A' star was so happy that she hit every form of social media, including Twitter, where she expressed her love for Ringer (and once again showed off her ring):

According to Us Weekly, Michalka and Ringer have been together for more than a year and a half. Congratulations to the happy couple!

Shine Bright Like a Diamond! See Hollywood's Best Engagement Rings