Why it adds new specification attribute but doesn't update them? Is it normal?

I noticed now that when I import products using their SKUs and products have specification attributes and when I try to update it, it creates the same but new specification attributes.

Example (product already has this attribute, I want to update it, not leave old one and add new one):
AttributeType  SpecificationAttribute  CustomValue  SpecificationAttributeOptionId  AllowFiltering  ShowOnProductPage  DisplayOrder
Option      Made in      12      True      True      0

12 is USA, I want to change it to Germany (it is 27).
When I import it back it becomes like this:
Product Bla Bla
Made in USA
Made in Germany

Is there any setting for updating specifications, but now add new ones?

Thanks.