angular: Test with Router injected - Cannot resolve all parameters for 'Router'

I have a component with the following constructor:

constructor(
    private _router: Router,
    private dispatcher: Observer<Action>,
    fb: FormBuilder
) { ... }

And if I run project everything works. But I need tests for it so here they are:

import {
it,
inject,
injectAsync,
beforeEachProviders,
TestComponentBuilder
} from "angular2/testing";

import {provide} from "angular2/core";
import {FormBuilder} from 'angular2/common';
import {Subject} from 'rxjs/Subject';
import {Router, RouteParams} from 'angular2/router';
// other imports ...

describe("SomeInfoEdit form", () => {

    const actions = new Subject<Action>(null);

    // provide our implementations or mocks to the dependency injector
    beforeEachProviders(() => {

        return [
            Router,
            FormBuilder,
            provide(dispatcher, { useValue: actions }),
            SomeInfoEdit
        ];
    });

    it('should have default data', inject([SomeInfoEdit], (component) => {
        expect(component.galtitle.value).toEqual("");
        expect(component.friendlyUrl.value).toEqual("");
        expect(component.isVisible.value).toBe(false);
    }));
...

This the test runs it gives me the error:

Cannot resolve all parameters for ‘Router’(?, ?, ?). Make sure that all the parameters are decorated with Inject or have valid type annotations and that ‘Router’ is decorated with Injectable.

I tried to put ROUTE_DIRECTIVES into beforeEachProviders but this doesn’t help. Is there a bug or am I doing something wrong?

I appreciate some explanation.