Rapper Juice WRLD’s cause of death has been ruled accidental “oxycodone and codeine toxicity,” according to the Cook County Medical Examiner’s Office.

The Chicago rapper, whose birth name was Jarad Higgins, died on Dec. 8 after he went into a seizure shortly after his private jet landed at Midway International Airport in Chicago. He had turned 21 a week prior to his death.

READ MORE: Chicago rapper Juice WRLD dies at 21

His girlfriend, Ally Lotti, told police that he had taken the painkiller Percocet and had battled a drug problem. TMZ reported that Juice had the seizure while walking through the airport and was rushed to a hospital in Oak Lawn, where he died.

Juice WRLD, who lived in Homewood, Ill., outside of Chicago, was named the top artist on SoundCloud in 2018, according to Billboard. His song “Lucid Dreams” made it to the number two spot on the Billboard Hot 100 chart and his second album, Death Race for Love, reached number one on the Billboard albums chart.

In a statement to TMZ last month, Juice’s mother Carmella Wallace said her son rapped about his own struggles with drug addiction because he wanted to help others who were also fighting addiction.

“We loved Jarad with all of our hearts and cannot believe our time with him has been cut short,” Carmella wrote in a statement. “As he often addressed in his music and to his fans, Jarad battled with prescription drug dependency.”

READ MORE: Rapper Juice WRLD reportedly ‘popped pills’ before he had seizure and went into cardiac arrest

Carmella added that “addiction knows no boundaries and its impact goes way beyond the person fighting it. Jarad was a son, brother, grandson, friend and so much more to so many people who wanted more than anything to see him defeat addiction. We hope the conversations he started in his music and his legacy will help others win their battles as that is what he wanted more than anything.”