Ibrahimovic met with Joshua in his dressing room before he fought Takam in Cardiff on Saturday.
“Zlatan loves his boxing and his mindset is phenomenal but he picked me up on something I said after my fight with Wladimir Klitschko earlier in the year,” Joshua told Skysports.
“He pointed out that I’d said ‘I’m not perfect, but I’m trying’. Then he said ‘No, no no. What you must is say is ‘I am perfect and I’m not trying.
Manchester United striker Ibrahimovic described Joshua as the “people’s champion”, adding that he is loved by everyone.
“He is not as good at boxing as I am at football… but he’s getting there,” he said.
“He’s a knockout artist and his personality is good because he is perfect and he is not trying. There are positive vibes all around him, he has good energy and expresses himself very well.
“That’s why everyone loves him. It’s why he’s the people champion.”