Lindsay Lohan allegedly annoyed Chaka Khan with her ''diva behaviour'' in rehab.
The 60-year-old singer sought treatment at the Cliffside medical centre in Malibu, California, at the same time as the 'Mean Girls' actress - who recently completed her 90-day court-ordered rehab stint - and was left furious by Lindsay's ''disruptive'' attitude.
A source told RadarOnline.com: ''Chaka was really cool about everything at Cliffside, but Lindsay just pushed all of her buttons to the point where she was aggravated and tired of Lindsay's s**t.
''Lindsay was just doing stupid stuff for attention, so Chaka told her she was childish and told her to grow up. She never lost it, but started yelling at Lindsay [and] told her to knock it off, asking her if she came to rehab to get well, or just to piss around.''
The 'Ain't Nobody' hitmaker was said to have been so frustrated with the 27-year-old starlet that she decided to end her time at Cliffside early and told fellow patients she ''hated'' Lindsay.
The insider added: ''Chaka was so annoyed with Lindsay. It got so bad that she refused to get in the same car with her or go to the same meetings with Lindsay. Chaka was so annoyed with Lindsay. It got so bad that she refused to get in the same car with her or go to the same meetings with Lindsay.''
Since leaving rehab, Lindsay has vowed to get her life together and has been taking advice from TV legend Oprah Winfrey, after recording a tell-all interview about her troubles for Oprah's OWN network.