Implementation wice_grid for one-to-many association

Image has a one-to-many association with Category:

# Category model:
has_many :images
# Image model:
has_one :category
Images migration file:
t.references :category, index: true, foreign_key: true

I'm trying to implement a grid view using the wice_grid gem. This works but one line is failing. The following works in the index view:

g.column name: 'Category', attribute: 'category_id', auto_reload: true, html: {id: 'grid-cells'} do |image|
  image.category_id
end

But this displays the number/id of the category, while I want it to display its name. If I try image.category instead of image.category_id there's an error:

PG::UndefinedColumn: ERROR:  column categories.image_id does not exist
LINE 1: SELECT  "categories".* FROM "categories" WHERE "categories"."image_id...

How can I have it display the category name instead of the id of the category?

Controller method:

def index
  @images_grid = initialize_grid(Image,
  # include: :category  # Do I need this? Tried it with and without
  per_page: 40)
end

via Chebli Mohamed