diff --git a/src/scheme/FiniteVolumesDiffusion.hpp b/src/scheme/FiniteVolumesDiffusion.hpp
index 72e5c399659604e56e9b45c884c0075d3f560fbf..182871147b1fda4633e02de31398eee4ba758912 100644
--- a/src/scheme/FiniteVolumesDiffusion.hpp
+++ b/src/scheme/FiniteVolumesDiffusion.hpp
@@ -167,8 +167,8 @@ private:
 	double sum2 = 0.;
 	for (int j=0; j<face_nb_cells(l); ++j) {
 	  int cell_here = face_cells(l,j);
-	  sum += Vj(cell_here)*uj(cell_here);
-	  sum2 += Vj(cell_here);
+	  sum += (1./Vj(cell_here))*uj(cell_here);
+	  sum2 += 1./Vj(cell_here);
 	}                
 	 
 	//m_Gl(l) = (1./face_nb_cells(l))*Fl(l)*sum;