Fast food lovers in shortage-plagued Venezuela are enjoying greasy French fries at McDonald's franchises here once again after the side dish went missing last winter.

McDonald's rolled out the fries' comeback on Monday with an ad campaign including a countdown on social media and large banners at franchises inviting customers to swap their fried yuca, a root crop also known as cassava, for the real thing.

Venezuela's shortages are driven in part by the country's tight currency controls, which make it hard to get dollars for imports. Potato imports fell 85 percent in 2014, before McDonald's took fries off the menu.

Sonia Ruseler, an Argentina-based spokeswollmlman for Arcos Dorados, which runs McDonald's restaurants in Latin America, says the company was able to bring the fries back by sourcing potatoes locally.