Sierra Leone’s presidential elections have made world history, reports OkayAfrica.

The latest election is notable because it is the first in the world to use blockchain technology, according to Business Insider. Each paper ballot was announced out loud by election official and then manually logged by Agora, the company that provided the technology.

Blockchain is commonly used by cryptocurrency companies to provide transparency in their transactions by storing data in a public record. Sierra Leone used the software for the same purpose.  Each vote was stored on a private blockchain that was only accessible by Agora employees and they published their tally results on a website. This reduces the probability of votes being tampered with–thus preventing voter fraud.

Citizens of Sierra Leone had to decide between Julius Maada Bio of the Sierra Leone People’s Party and Samura Kamara of All People’s Progress, the party that currently governs the nation. Although Bio and Kamara are opponents, the two have a long history as allies.

In 1996, Bio gained power through a military coup that ousted then-leader Valentine Strasser. He stepped down after three months, when another leader was democratically elected. Before his departure, he named Kamara as the minister of finance.

Voting began last Wednesday, and ended with Bio barely winning with 43.3 percent of the vote to Kamara’s 42.7. However, there will be a run-off because a candidate must win 55 percent of the vote to be elected. A run-off is scheduled for March 27.