In an interview that aired Sunday on NBC’s “Meet the Press,” Sen. Elizabeth Warren (D-Mass.) said there is no reason to take a DNA test to prove her heritage as she’d learned all she needs to learn from her mom, dad and grandparents about her ancestry. That evening, Donald Trump Jr., President Trump’s eldest son, took a jab at Warren regarding her stance.

When pressed to clear up questions about her unproven Native American lineage with the test, Warren said, “I know who I am,” and dismissed the notion that she should prove it.

In his tweet, Trump Jr. suggested an alternative to testing. He wrote: Why not simply “identify” as Native American. Problem solved. #yourewelcome.