Fans know that Jeopardy! is the toughest game show on television. A Naperville contestant learned that host Alex Trebek can be a little tough, too.

Returning Jeopardy! champion, Naperville's Lisa Mueller really liked writing to shows and celebrities when she was a child. But a letter she once penned to Sesame Street‘s Big Bird ruffled Alex Trebek‘s feathers.

Here's the exchange:

After the commercial break, Trebek joked, “Our champion, Lisa Mueller, told me that when she leaves Jeopardy! she is going to write me a very long letter.”

And Alex will be looking for typos.