diff --git a/energy_selfconsumption/wizards/define_invoicing_mode_wizard.py b/energy_selfconsumption/wizards/define_invoicing_mode_wizard.py
index 955c0f31b8886826e8b0a91c2e412a602d96af3a..49bec96f08abb24a978c7021921d3c2cad272ab7 100644
--- a/energy_selfconsumption/wizards/define_invoicing_mode_wizard.py
+++ b/energy_selfconsumption/wizards/define_invoicing_mode_wizard.py
@@ -89,6 +89,7 @@ class ContractGenerationWizard(models.TransientModel):
             "company_id": self.env.company.id,
             "qty_type": "variable",
             "qty_formula_id": formula_contract_id.id,
+            "uom_id": product_id.uom_id.id,
             # Values are formatted in contract_generation_wizard
             "name": """CUPS: {code}\nOwner: {owner_id}\nInvoicing period: #START# - #END#""",
         }