(CNN) They were billed as innovative, next-generation banknotes with added security -- but Australia's new $50 note also contain another feature: An unfortunate typo.

The $50 note (US$34.9) which entered general circulation last October has anti-counterfeiting measures including a swan that appears to fly and a holographic 50 that reverses when the note is moved.

Around 400 million new notes were printed -- and 46 million of them are in circulation, according to the central bank the Reserve Bank of Australia (RBA). The total value of the notes in circulation is around $2.3 billion (US$1.6 billion).

But an eagle-eyed observer has spotted a problem with the new notes: The word "Responsibility" is missing an "i."

Australia's Triple M radio station Thursday posted a close-up photo of the note on its Instagram account, showing the error.

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