Providing a mock to another mocks constructor?

I'm curious about whether I'm doing things right here, as I'm new to testing.

I have two services (so far), AuthService and CommentService. CommentService depends on AuthService, and AuthService depends on a 3rd party class (\SlimSession\Helper).

In my unit test for AuthService I simply mock \SlimSession\Helper and provide the mock to the constructor.

Now, in my test for CommentService I mock the AuthService and provide it to the constructor of the CommentService. But I must also create a mock of the \SlimSession\Helper again to provide it to the constructor of my mocked AuthService.

$session = $this->getMockBuilder('\SlimSession\Helper')
  ->getMock();

$auth = $this->getMockBuilder('\App\Service\AuthService')
  ->setConstructorArgs([$session])
  ->getMock();

$auth->expects($this->any())->method('isLoggedIn')->willReturn(false);
$auth->expects($this->any())->method('getLoggedInUserId')->willReturn(0);

Is this right? It seems a bit silly to have to provide a (mock) dependency to a mock object, since it won't use that dependency anyway.

My question regards PHPUnit in particular, but I guess it could be made generally for unit testing.