Laravel Model Bind with repository and Mockery fails

Question

I am trying to test my service with Mockery. I have bound the route param {user} to my service:

$repo = 'Services\\UserService';
$router->bind('user', function($id, $route) use($repo) {
    return $this->app->make($repo)->get($id);
});

When I run my first test it succeeds.

$mocked = Mockery::mock('UserService');
\App::instance('UserService', $mocked);

$mocked->shouldReceive('create')
       ->once()
       ->andReturn($user);

When my next test runs it fails

$mocked = Mockery::mock('UserService');
\App::instance('UserService', $mocked);

$mocked->shouldReceive('update')
       ->once()
       ->andReturn('1');

Dumping out in the router->bind method

dump(get_class($this->app->make($repo));

I get Services\UserService the first time but the second time I get Mockery_0_Services_UserService and then this error:

testing.ERROR: exception 'BadMethodCallException' with message 
'Method Mockery_0_Services_UserService::get() does not exist on this mock object

I would assume that it has something to do with the App::instance method but I am not sure.

What could be the issue here?