Wrong.

In Australia, mandatory voting is compelled real or virtual attendance.

You are required to cast or mail in an anonymous response, that response can be blank, a vote for someone not listed, a regular vote, a donkey vote, paper with many pictures of various genitalia, etc.

No speech is compelled, no pen to paper is compelled, just that registered voters are ticked off the rolls and those registered that don't respond provide at least a weak excuse (my grandmother was sick that day) or face a nominal fine (eventually).

Think of it a citizens part to play in a democracy, the commitment to at least pay attention to the government hired by and paid for by citizens.