Apollo 11 astronaut and the first man on the moon Neil Armstrong refused to sign an autograph for U.S. House of Congress speaker Nancy Pelosi, according to news website rollcall.com.
California Democrat Pelosi reportedly asked the publicity-shy former astronaut to autograph something for her son.
The pair were at an event marking the 40th anniversary of Armstrong's "giant leap for mankind," held at the Cannon House Office Building in Washington last Tuesday.
"I'm sorry, I don't do that anymore," was Armstrong's purported response.
Armstrong famously refuses all autograph requests - no matter how powerful the person asking for it - apparently fearing forgeries and those making large amounts of money from his signature.
This will be good news to autograph investors. The continued rarity and finite supply of Armstrong signatures has seen it fetch prices of around £5,000.