The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) has slightly downgraded its estimate of seismic event of North Korea’s recent nuclear test, while confirming the 2016 explosion was certainly man-made.

The technical analysis was made available to all member states of the Comprehensive Nuclear-Test-Ban Treaty, and can be found on the CTBTO’s website.

“The initial estimate of the event’s magnitude was 4.9, which was revised to 4.85 in the course of further analysis,” it website reads.

While the downgrade is small, as pointed outby Bruce Bennett, senior defense analyst at the Rand cooperation, the Richter scale is logarithmic, not linear.