bUnit - Cannot provide a value for property "objectService" on type "directory" There is no registered service of type "IobjectService"

I'm attempting to unit test Blazor components for UI based things (when this button is pressed, these input fields should be displayed, etc). This is how my test is constructed:

[Test]public void TestPageRendering(){    using var ctx = new Bunit.TestContext();    ctx.Services.AddScoped<ObjService>();    var cut = ctx.RenderComponent<componentToTest>();    cut.Markup.Contains("blah blah");}

The @inject statement at the top of the componentToTest is as follows:

@inject IobjectService objectService

The error I receive is: Cannot provide a value for property "objectService" on type "directory" There is no registered service of type "IobjectService"

I assume there's an issue with a naming convention? Can't put my finger on it?