Ariana Grande seems to be paying tribute to her late ex Mac Miller on Twitter. 

On what would have been Miller's 27th birthday, Grande tweeted out a simple message, without directing it at anyone in particular.

"miss u," she wrote.

Grande has shared several tributes to Miller since he passed away in September. Grande and Miller dated for 18 months and she's grieved for him openly on social media and in her songs

"I adored you from the day I met you when I was nineteen and I always will," she captioned a video of Miller in the week following his death. "I can’t believe you aren’t here anymore. I really can’t wrap my head around it. We talked about this. So many times. I’m so mad, I’m so sad I don’t know what to do. You were my dearest friend. For so long. Above anything else. I’m so sorry I couldn’t fix or take your pain away...I hope you’re okay now. rest."

Grande, who suffered through a broken engagement and the death of Miller in 2018, posted a year-end Instagram that noted how tough the year was for her.