(CNN) Chitetsu Watanabe turns 113 next month, but he got an early birthday present from Guinness World Records, which confirmed that he is the world's oldest living man.

He was presented with a certificate on Wednesday at the nursing home where he lives in Niigata, Japan -- he's 112 Years, 344 days old, according to Guinness

Watanabe made a calligraphy banner for the occasion that says "World No. 1."

In an interview last year, Watanabe said his secret to longevity is "not to get angry and keep a smile on your face."

He also loves sweets, like brown sugar, but he mostly enjoys things like custards and the filling in cream puffs these days because he's lost his teeth.

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