nodejs jasmine test fails on 'expect' | 'undefined' is not a function (evaluating 'expect(true).toBe(true)')

Question

I have setup a simple spec:

describe("A suite", function() {
  it("contains spec with an expectation", function() {
    expect(true).toBe(true);
  });
});

And when I run grunt jasmine I get:

Running "jasmine:src" (jasmine) task
Testing jasmine specs via PhantomJS

 A suite
   × contains spec with an expectation
     TypeError: 'undefined' is not a function (evaluating 'expect(true).toBe(tru
e)') in file:///C:/Users/long-path-to-spec/testing-spec.js (line 4) (1)


1 spec in 0s.
>> 1 failures
Warning: Task "jasmine:src" failed. Use --force to continue.

Aborted due to warnings.

It seems to be running the spec... it seems to know what 'describe' and 'it' are, but it seems to be unaware of 'expect'?

Any ideas?