diff --git a/atomisticparsers/gromacs/parser.py b/atomisticparsers/gromacs/parser.py
index 4f2a43a..b8f0e96 100644
--- a/atomisticparsers/gromacs/parser.py
+++ b/atomisticparsers/gromacs/parser.py
@@ -634,7 +634,7 @@ def __init__(self):
         self.mdp_std_filename = "mdout"
         self.xvg_parser = GromacsXvgParser()
         self.input_parameters = {}
-        self._gro_energy_units = ureg.kilojoule * MOL
+        self._gro_energy_units = (ureg.kilojoule / ureg.avogadro_number) * ((1000 * ureg.joule) / ureg.kilojoule)
         self._thermo_ignore_list = ["Time", "Box-X", "Box-Y", "Box-Z"]
         self._base_calc_map = {
             "Temperature": ("temperature", ureg.kelvin),