diff --git a/src/Mod/Fem/femmesh/meshtools.py b/src/Mod/Fem/femmesh/meshtools.py
index e8bc641764..c3f1cd0a96 100644
--- a/src/Mod/Fem/femmesh/meshtools.py
+++ b/src/Mod/Fem/femmesh/meshtools.py
@@ -1426,6 +1426,7 @@ def build_mesh_faces_of_volume_elements(
         FreeCAD.Console.PrintLog("VolElement: {}\n".format(veID))
         vol_node_ct = len(femelement_table[veID])
         face_node_indexs = sorted(face_nodenumber_table[veID])
+        node_numbers = ()
         if vol_node_ct == 10:
             FreeCAD.Console.PrintLog("  --> tetra10 --> tria6 face\n")
             # node order of face in tetra10 volume element