Stephen Harper makes a grammatical error on Twitter

We're all guilty of grammar faux pas every now and again — especially on social media.

It's not a big deal — unless you're the prime minister of Canada.

Stephen Harper, or one of Stephen Harper's ghost-tweeters, made a grammatical error on Monday while posting a picture in commemoration of President Barack Obama's inauguration.

The grammatical error — of course — is the 'I.' The tweet should have read "One of my favourite photos of @barackobama and me."

[ Full coverage of Barack Obama's presidential inauguration ]

Some of Harper's Twitter followers weren't afraid to let him know about his error.

And, alas, the ahem, prime minister made the change: