A little landscaping has created a minor border crisis between the two countries.

Three French history enthusiasts have spent the past couple of years looking at century-old maps while slowly walking the border between France and Belgium. The men have been carefully noting the locations of the heavy stones that mark that line, and sometimes just trying to find them underneath... everything that's grown over and around them since they were placed between the two countries in the early 19th century.

During one of their recent outings, they noticed that one of the border stones looked like it had been moved about seven feet from where it should've been—and they were right. According to La Voix du Nord, a farmer who lives on the Belgian side apparently shifted one of the 150-kilogram (330-pound) border markers, slightly expanding his property at France's expense. (His French neighbor is the one who snitched on him.)

Belgian border
Credit: Nclauzing/Getty Images

Now the mayors of the villages on both sides of the newly rearranged border are trying to get the farmer to put the stone back where it was. "We know exactly where the stone was before, right next to a tree," David Lavaux, the mayor of Erquelinnes, Belgium, told CNN.

"In 2019, during the 200th anniversary, they were geo-localized very precisely. The stones were placed there in 1819 following the defeat of Napoleon, and the year is inscribed on them. It should be resolved [on Wednesday]. We are about to find the person that moved the stone, so we can avoid any troubles." (In a Facebook post, Lavaux joked that Belgium was enlarged, but "the French don't agree" with the new border.)

The BBC reports that Belgian authorities are trying to get in touch with the farmer to ask him to put the stone back where he found it. If that doesn't happen, the two countries will have to "summon a Franco-Belgian border commission" to try to resolve the situation—even though that particular group hasn't been active since 1930.

"As far as I know, these kinds of 'border disputes' between Belgium and France have barely taken place between 1820 and today," a University of Antwerp historian told VICE. "I do guess that if they would have to meet again, they would handle the matter in a rather neutral and friendly way."

The 390-mile long border between Belgium and France was formally agreed upon in 1820, five years after Napoleon's French army was defeated at the Battle of Waterloo, and France had to redraw its own borders. Those stones—including the one that the farmer took it upon himself to relocate—were placed in 1819. (They're marked with an F for France on one side and an N for the Netherlands on the other, since Belgium didn't become independent from the Netherlands until 1830.)

Regardless, the mayors on both sides think that they should be able to resolve this ultra-minor dispute without having to call in the troops. "We should be able to avoid a new border war," the mayor of French village Bousignies-sur-Roc said.