Mozilla CEO John Lilly has admitted the Firefox maker’s relationship with Google has become “more complicated” since the company launched its own browser.

Mozilla is dependent on Google for the vast majority of its revenue and has previously worked closely with the search king’s engineers on the development of Firefox.

But that relationship appears to have cooled since Google released Chrome in the summer. “We have a fine and reasonable relationship,” John Lilly, Mozilla’s CEO, said in an interview with Computerworld. “But I’d be lying if I said that things weren’t more complicated than they used to be.”