diff --git a/stock_quant_manual_assign/wizard/assign_manual_quants.py b/stock_quant_manual_assign/wizard/assign_manual_quants.py
index 17d3d40f5269..09b89365aa14 100644
--- a/stock_quant_manual_assign/wizard/assign_manual_quants.py
+++ b/stock_quant_manual_assign/wizard/assign_manual_quants.py
@@ -185,7 +185,7 @@ def _onchange_selected(self):
             # validation.
             quant_qty = self.on_hand - self.reserved
             remaining_qty = self.assign_wizard.move_qty
-            self.qty = min(quant_qty, remaining_qty)
+            self.qty = max(0, min(quant_qty, remaining_qty))
 
     @api.constrains("qty")
     def _check_qty(self):