Dorsa Derakhshani was thrown off the Iranian national chess team not because of the mind in her head, but what she was wearing on that head.

The 18-year-old female grand master, competing at the Tradewise Gibraltar Chess Festival in the British territory last month, adorned her head with a plain headband. She did not wear a hijab, the headscarf that has been mandatory for females in Iran since 1979. And though she finished 118th out of 255 in the tournament, the break from the religious custom cost her a spot on the team.

And she wasn’t alone. Her brother, Borna Derakhshani, reportedly is now banned, too, the 15-year-old’s crime being playing against an Israeli opponent in the tournament. Iran does not recognize the state of Israel, and Iranians are not allowed to legitimize Israelis by competing against them.

The punishments were announced by Mehrdad Pahlevanzadehhead, the head of the Iranian Chess Federation on Monday.

“Unfortunately, what shouldn’t have happened has happened. Our national interests have priority over everything,” Pahlevanzadeh said, via Radio Free Europe, also banning the siblings from competing in Iran tournaments. “…We’re considering measures that will prevent similar incidents from taking place in future tournaments.”

It’s a can’t-win for the Iranian competitors. Last year, at a Switzerland chess tournament, Iranian Ehsan Ghaem-Maghami withdrew when he drew an Israeli player in the fifth round. He’s still allowed on the national team, but was eliminated from the tournament.

Also last year, American Nazi Paikidze boycotted an Iranian chess tournament in a boycott of the hijab.

Neither Borna nor Dorsa Derakhshani has spoken publicly about being banned.