Government surveyors are set to announce today that the official height of the Washington Monument has changed: it’s now shorter, although not by much.

The new official height will be 554 feet and 7 and 11/32nd inches, a drop of 10 inches from its original height of 555 feet and 5 and 1/8th inches, based on a measurement from the floor of the main entrance to the very top of the iconic obelisk, according to an Associated Press report.

The measurement changes an official record of the monument’s height that had stood for more than 130 years.

The National Geodetic Survey, which conduct the measurement, said the reason for the lower height had nothing to do with any actual shrinking of the monument at all, but rather a different in how building measurements are conducted in the modern day. Dru Smith, chief geodesist at NGS, said the modern building measurements call for a different base point that what was used in 1884, when the original measurement was made shortly upon completion, according to the AP report.

The international standard, which was created by the Council of Tall Buildings and Urban Habitat, measures from the lowest open-air pedestrian entrance of the building. The original 1884 measurement probably used four brass markers as a base for measurement, which are still located on the grounds of the Washington Monument and about 9 inches below ground on each corner of the monument.

Measurements from those brass markers to the top in 1999 and 2014 confirmed the original measurement, meaning that 1884 measurement was actually incredibly accurate, but now no longer up to modern building measurement standards.

There have been some small physical changes to the monument that may have altered its height slightly: specifically, the pyramid-shaped tip of the obelisk has been rounded off a little bit over the many years that it has stood tall in Washington. The tip, made of aluminum, likely became rounded from frequent lightning strikes that melted the aluminum slightly. The surveyors confirmed in this most recent measurement that, yes, about 3/8ths of an inch had been melted off the very top of the monument.

That further indicates the 1884 measurement was in 3/4ths of an inch of the latest survey’s findings based on the original brass markers.