diff --git a/addons/stock_landed_costs/stock_landed_costs.py b/addons/stock_landed_costs/stock_landed_costs.py
index 2efcfc160c7..94086c120f1 100644
--- a/addons/stock_landed_costs/stock_landed_costs.py
+++ b/addons/stock_landed_costs/stock_landed_costs.py
@@ -268,7 +268,7 @@ class stock_valuation_adjustment_lines(osv.osv):
                 'former_cost_per_unit': 0.0,
                 'final_cost': 0.0,
             }
-            result[line.id]['former_cost_per_unit'] = (line.former_cost / line.quantity or 1.0)
+            result[line.id]['former_cost_per_unit'] = (line.former_cost / line.quantity if line.quantity else 1.0)
             result[line.id]['final_cost'] = (line.former_cost + line.additional_landed_cost)
         return result