Save image file to database in Rails

I need to save image from file to PostgreSQL database as binary. Trying to do it like this:

image_file = File.open("image.png", "rb") { |file| file.read }
Image.create(product_id: product_id, image: image_file)

This code gives me the following error:

string contains null byte

Using paperclip or similar, or converting binary to base64 are not an option.