Relationships with column in same table

I have a category table. I also offer sub-categories on this app. I have a foreign key ('parent') on my categories table which refers to the 'id' column on the same table.

My relationship looks like so

public function parentcat()
    {
        return $this->belongsTo(Category::class, 'parent');
    }

When I run Tinker..

$category = \App\Category::find(2)
$category->parentcat->name

It returns the name of the parent category as expected.

In the view; I am outputting the results in a table. If I print

$category->parentcat

I get

// The model object. (Laracasts strips it out though!) Cheers @JeffreyWay  :p

But if I add

$category->parentcat->name

I get an exception 'Trying to get property of non-object'

What am I doing wrong?

TIA, Mark