Over at online forums site Reddit, users uncovered a glitch in Apple’s Siri when they ask the virtual personal assistant to define the word “mother.” The first definition is about what you’d expect and says it’s a woman who has children. But right after delivering the first definition, Siri asks you if you want to hear the second definition. Say yes, and Siri will tell you that the word “mother” is short for “motherf—-r.”

According to the Reddit users, whose findings were earlier reported on by Gizmodo, the second definition is available on any iPhone, Mac, or other Apple product they queried Siri on. I tried it out on my range of Apple products and was similarly given the option to hear the second definition and the expletive. If you want to try it out for yourself, then, be sure children aren’t within earshot.

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Of course, Apple didn’t intentionally design Siri to return an expletive when defining mother. Instead, when users query Siri for a definition, the service looks for it in the Oxford Dictionary. The second definition in that dictionary lists the expletive.

Apple did not immediately respond to a Fortune request for comment on the Siri response. However, the company has dealt with odd or improper Siri responses in the past and has simply updated those to remove them or correct them. It’s possible that Apple will scrub the second mother definition from Siri and stop it from returning that result on any of the devices on which the virtual personal assistant is installed.