diff --git a/common/python/nomadcore/unit_conversion/unit_conversion.py b/common/python/nomadcore/unit_conversion/unit_conversion.py
index 134cbf1a94356d48876b51307a1f547b1577b3f9..e707756eac14c967044399cfbd2202a3ea83e864 100644
--- a/common/python/nomadcore/unit_conversion/unit_conversion.py
+++ b/common/python/nomadcore/unit_conversion/unit_conversion.py
@@ -21,6 +21,7 @@ logging.getLogger("pint").setLevel(logging.ERROR)
 ureg = UnitRegistry()
 ureg.define('forceAu = hartree / bohr')
 ureg.define('inversecm = 1.9864475e-23 * joule')
+ureg.define('mubohr = 9.274009994e-24 J / T')
 
 
 @cachetools.cached(cache={})