Former finance minister Tito Mboweni happily tweeted on Friday that Kigali, the capital of Rwanda, was "an African example of the possible dream".
He missed Kigali so much, he said, and one could see why.
Above the tweet were four pictures of a beautiful African city.
The only problem is that the pictures were of Kampala, the capital of Uganda, which the twitterverse was not slow to point out.
Clayson Monyela, the Department of International Relations and Cooperation's head of public diplomacy, made a pointed response: "This is Kampala. I think it's time I arranged a proper and comprehensive briefing on the Kigali file for you."
Mboweni might have thought his tweet would be controversial for other reasons.
He said he was going there for lunch soon with "guess who?" (Presumably meaning Paul Kagame, the president of the country.)
Many people regard Kagame as a ruthless dictator who runs a militaristic surveillance state that assassinates its opponents in foreign countries, including South Africa.
Former Gauteng premier Mbhazima Shilowa chimed in: "I must visit it soon. I'm told it is a great city with a great leader who doesn't tolerate dissent. Saw a female candidate arrested and thrown in jail for daring to contest the leader."
Others suggested that Mboweni must have tweeted after taking something fairly strong to accompany his nightly serving of canned pilchards.