diff --git a/PVTPackage/source/MultiphaseSystem/PhaseModel/BlackOil/BlackOil_WaterModel.cpp b/PVTPackage/source/MultiphaseSystem/PhaseModel/BlackOil/BlackOil_WaterModel.cpp
index 163928e..943ee78 100644
--- a/PVTPackage/source/MultiphaseSystem/PhaseModel/BlackOil/BlackOil_WaterModel.cpp
+++ b/PVTPackage/source/MultiphaseSystem/PhaseModel/BlackOil/BlackOil_WaterModel.cpp
@@ -23,7 +23,7 @@ void BlackOil_WaterModel::ComputeProperties(double P, PhaseProperties& props_out
   props_out.MoleComposition.value = {0.,0.,1};
   props_out.MolecularWeight.value = m_SurfaceMolecularWeight;
   props_out.MassDensity.value = m_SurfaceMassDensity / (m_PVTW.Bw * exp(-m_PVTW.Compressibility*(P - m_PVTW.ReferencePressure)));
-  props_out.MoleDensity.value = props_out.MassDensity.value*props_out.MolecularWeight.value;
+  props_out.MoleDensity.value = props_out.MassDensity.value/props_out.MolecularWeight.value;
   props_out.Viscosity = m_PVTW.Viscosity;
 }