diff --git a/src/geouned/GEOUNED/Conversion/CellDefinition.py b/src/geouned/GEOUNED/Conversion/CellDefinition.py
index 50ded8d5..b8336990 100644
--- a/src/geouned/GEOUNED/Conversion/CellDefinition.py
+++ b/src/geouned/GEOUNED/Conversion/CellDefinition.py
@@ -712,7 +712,7 @@ def GenTorusAnnexVSurface(face, Vparams, forceCylinder=False):
         Apex = face.Surface.Center + za * axis
         semiAngle = abs(math.atan(d1 / (z1 - za)))
 
-        ConeAxis = axis if za < 0 else -axis
+        ConeAxis = axis if (z1 - za) > 0.0 else -axis
 
         Vmid = (Vparams[0] + Vparams[1]) * 0.5
         pMid = face.valueAt(0, Vmid) - face.Surface.Center