Accounts.onLogin not firing on client side

I don’t understand why this isn’t firing on the client side:

/lib/permissions.js

Accounts.onLogin(function () {
if(Meteor.isClient) {
console.log(‘onLogin - client’);
Meteor.logoutOtherClients(function(error) {});
} else {
console.log(‘onLogin - server’);
}
});

The log shows as expected on the server side but not on the client.

This leads me to believe I must be missing something rather obvious - but I don’t know what it is. Some help will be appreciated.

Thanks