Jenson Button has featured a tribute to his father on his helmet for this week's Formula 1 pre-season test in Jerez.
John Button, who attended all but one of his son's grands prix, died from a suspected heart attack earlier this month.
McLaren tweeted a picture of the helmet, which shows cartoon character Papa Smurf, alongside the message "RIP Papa".
The 2009 world champion posted the fastest time in yesterday's session.