TypeError: Object explicit failure has no method 'call'

I don't completely know for sure whether this is a problem with Mocha or if it's a problem with expect.js but either way, whenever I explicitly fail, I get that message rather than whatever I have my fail message as.
Example:
## test.js:

``` js
describe('This is', function(){
var dude = new Frankenstein($("body"), window);
it("a test that will fail", function(){
expect().fail(" I, the test, did fail... therefore I passed. I am so meta.");
});
});
```
## terminal:

``` bash
$ mocha test.js
.
1 failing

1) This is a test that will fail:
TypeError: Object I, the test, did fail... therefore I passed. I am so meta. has no method 'call'
at Assertion.assert (/Users/aluhring/Sites/default/node_modules/expect.js/expect.js:99:27)
at Assertion.fail (/Users/aluhring/Sites/default/node_modules/expect.js/expect.js:470:10)
at Context. (/Users/aluhring/Sites/default/public/tests/_podder.js:99:22)
at Test.Runnable.run (/usr/local/lib/node_modules/mocha/lib/runnable.js:211:32)
at Runner.runTest (/usr/local/lib/node_modules/mocha/lib/runner.js:372:10)
at /usr/local/lib/node_modules/mocha/lib/runner.js:448:12
at next (/usr/local/lib/node_modules/mocha/lib/runner.js:297:14)
at /usr/local/lib/node_modules/mocha/lib/runner.js:307:7
at next (/usr/local/lib/node_modules/mocha/lib/runner.js:245:23)
at Object._onImmediate (/usr/local/lib/node_modules/mocha/lib/runner.js:274:5)
at processImmediate [as _immediateCallback] (timers.js:330:15)
```

Being that the test is supposed to fail and that the test is failing, I'm getting the result I need but I'm not trying to get a stack trace of an error that I want to exist... but that's what I'm getting.
Is there something I'm doing wrong or is this what's supposed to happen?
Any help or direction would be appreciated.