Can't install - mysqli can't be found

When I try to install, I get stuck on this step:

Piwik requires either the mysqli extension or both the PDO and pdo_mysql extensions.

However, the php version i’m using has both of these extensions already built in. What to do now?

Check your phpinfo(). “mysqli” (note the trailing ‘i’) is different from “mysql” (without the trailing ‘i’). If you don’t have mysqli, the alternative requires both “PDO” and “pdo_mysql” extensions to be present.