diff --git a/addons/hr_timesheet/models/hr_timesheet.py b/addons/hr_timesheet/models/hr_timesheet.py
index 96ba98a2431..1b669377921 100644
--- a/addons/hr_timesheet/models/hr_timesheet.py
+++ b/addons/hr_timesheet/models/hr_timesheet.py
@@ -338,7 +338,8 @@ class AccountAnalyticLine(models.Model):
             if not vals.get('partner_id'):
                 vals['partner_id'] = data.partner_id.id
             if not vals.get('product_uom_id'):
-                vals['product_uom_id'] = uom_id_per_company.get(account_per_id[vals['account_id']].company_id, False)
+                company = account_per_id[vals['account_id']].company_id or data.company_id
+                vals['product_uom_id'] = uom_id_per_company.get(company.id, company.project_time_mode_id.id)
         return vals_list
 
     def _timesheet_postprocess(self, values):
diff --git a/addons/hr_timesheet/tests/test_timesheet.py b/addons/hr_timesheet/tests/test_timesheet.py
index b5b81687f2f..920abffdb0c 100644
--- a/addons/hr_timesheet/tests/test_timesheet.py
+++ b/addons/hr_timesheet/tests/test_timesheet.py
@@ -552,8 +552,17 @@ class TestTimesheet(TestCommonTimesheet):
     def test_create_timesheet_with_companyless_analytic_account(self):
         """ This test ensures that a timesheet can be created on an analytic account whose company_id is set to False"""
         self.project_customer.analytic_account_id.company_id = False
-        timesheet = self.env['account.analytic.line'].with_user(self.user_employee).create({'unit_amount': 1.0, 'project_id': self.project_customer.id})
-        self.assertFalse(timesheet.product_uom_id, "The product_uom_id of the timesheet should be set to False for its analytic account has no company_id")
+        timesheet_with_project = self.env['account.analytic.line'].with_user(self.user_employee).create(
+            {'unit_amount': 1.0, 'project_id': self.project_customer.id})
+        self.assertEqual(timesheet_with_project.product_uom_id, self.project_customer.company_id.project_time_mode_id,
+                         "The product_uom_id of the timesheet should be equal to the project's company uom "
+                         "if the project's analytic account has no company_id and no task_id is defined in the vals")
+        timesheet_with_task = self.env['account.analytic.line'].with_user(self.user_employee).create({
+            'unit_amount': 1.0, 'task_id': self.task1.id
+        })
+        self.assertEqual(timesheet_with_task.product_uom_id, self.task1.company_id.project_time_mode_id,
+                         "The product_uom_id of the timesheet should be equal to the task's company uom "
+                         "if the project's analytic account has no company_id")
 
     def test_create_timesheet_with_default_employee_in_context(self):
         timesheet = self.env['account.analytic.line'].with_context(default_employee_id=self.empl_employee.id).create({