South Korea's antitrust regulator has fined Google about $177 million.
That's for blocking customized versions of its Android operating system for smartphones.
And it's the tech giant's second setback in the country in less than a month.
On Tuesday (September 14) the Korea Fair Trade Commission said that Google's contract terms with device makers amounted to abuse of its dominant market position.
Its concerns centered on clauses that prevent manufacturers from developing their own versions of Android.
The KFTC said that restricted competition in the market for operating systems.
Google says it will appeal, arguing that the ruling ignores the benefits of Android's compatibility with other programs.
But the fine comes on the very day that a measure dubbed the 'anti-Google law' comes into effect.
The South Korean bill bans app store operators from requiring software developers to use their payment systems.
That effectively stops Google and Apple from charging commissions on in-app purchases - a major revenue stream for the tech titans.