Rihanna. (Stefan Wermuth/Reuters)

The singer was forced to cancel a show in Malmo, Sweden, and apologized to fans on Twitter. To prove just how sick she was, Riri tweeted a photo of her arm hooked up to an IV drip.

”I was so excited to perform for you all,” Rihanna said in a statement. “It would have been a great time ... so much better than being sick with the flu, ugh! I'm really disappointed I couldn’t be there.”

Flu or no flu, the show must go on. Rihanna, who is touring in Europe through December, is expected to perform in Stockholm tonight.