Bieber knocked out cold during Paris show

Justin Bieber suffered a concussion after walking into a glass wall, backstage of his Paris concert. Photo / AP

Justin Bieber is "taking it easy" after suffering a concussion.

The 18-year-old singer walked into a glass wall backstage during his concert in Paris on Thursday.

The Boyfriend performer managed to complete his set on stage, but passed out briefly in his dressing room afterwards.

Doctors tell TMZ that Justin suffered a concussion, but he has reassured fans that he is fine.

He tweeted: "Just smacked my head and needed some water. All good. I'm Canadian. We are tough. LOL. It's all good. Just gotta take it easy the rest of the night. Back at it again for you guys tomorrow. Thanks."

The news of his accident reached his fans before his own mother.

He continued: "The fact you all knew what happened before my mom even did is impressive. LOL. I have amazing fans," he wrote. "Very grateful for your love."

This isn't the first time Bieber has hit his head walking into glass. Justin was caught on camera walking into a revolving glass door in May 2010 and he made a joke about getting revenge on the transparent material.

He wrote: "I will see u again glass. I will have my revenge. Bieber vs glass. MGM Las Vegas 2013. LOL. Gotta Laugh At Yourself."

- Bang! Showbiz