Oops.

Amazon on Wednesday apologized to a British customer who called on the online retail giant to “immediately” remove from sale a book disguised as a puppy-training manual that in fact contains a full reprint of a 1930s Nazi propaganda book eulogizing Adolf Hitler’s achievements, ideology and work.

“We apologize to the customer for this issue, which was caused by a one-off printing issue with a supplier. Our supplier has confirmed that steps have been taken to ensure it doesn’t happen again,” Amazon said in a statement.

Lorraine Phipps purchased on Amazon Puppy Training by Jenna Jimenez on March 2 and was shocked to find instead, printed inside the book, Adolf Hitler, 1931-1935: Pictures From the Life of the Führer, originally published in 1936 with a foreword by leading Nazi party figure Hermann Göring. It contains 203 photographs and has accompanying text authored by some of the highest-ranking Third Reich officials, including propaganda chiefs Joseph Goebbels and Otto Dietrich.

“When my husband and I went to read it, despite the cover being as expected, it was actually a reprinting of a 1936 pro-Nazi propaganda book,” she said.