(CNN) -- If Anne Frank had not died a teenager in a Nazi concentration camp in 1945, Justin Bieber hopes she would have been his devoted fan.
That's what Bieber, 19, wrote in the guestbook at the Anne Frank House when he visited the Friday, according to the Amsterdam site.
"Truly inspiring to be able to come here. Anne was a great girl. Hopefully she would have been a belieber," Bieber wrote. The tourist site posted the message on its Facebook page.
Adolescent and teen girls obsessed with the Canadian singer are known as "Beliebers."
Bieber, who is in the middle of a European tour, stopped by the Anne Frank House between his Antwerp, Belgium, concert and a Saturday performance in Arnhem, Netherlands. He told fans on Twitter it was a "chill day."
Bieber visited the house "together with his friends and guards" Friday night, according to the site's official Facebook page. The Anne Frank House confirmed to CNN that its Facebook post carrying Bieber's message was authentic.
"Fans were waiting outside to see a glimpse of him. He stayed more than an hour in the museum," the Facebook page said.
Anne Frank's story
Frank was 13 when she and her family began hiding in a dark and damp "secret annex" of the house to escape the German round up of Jews in Holland in July 1942. She never left the house for two years, spending much of her time writing in her diary until she and her family were found and arrested by Nazis in August 1944.
Anne Frank died of typhus in the Bergen-Belson concentration camp in March 1945. Her diary survived to tell her tragic and inspiring story.
Bieber's representatives did not immediately respond to CNN's request for comment Sunday, but visitors to the Anne Frank Facebook page had plenty to say.