diff --git a/addons/stock/i18n/stock.pot b/addons/stock/i18n/stock.pot
index 42fb129524e..7f348c16a60 100644
--- a/addons/stock/i18n/stock.pot
+++ b/addons/stock/i18n/stock.pot
@@ -7964,6 +7964,14 @@ msgid ""
 "instead."
 msgstr ""
 
+#. module: stock
+#: code:addons/stock/models/product.py:0
+#, python-format
+msgid ""
+"This product's company cannot be changed as long as there are quantities of it"
+" belonging to another company."
+msgstr ""
+
 #. module: stock
 #: model:ir.model.fields,help:stock.field_stock_change_product_qty__new_quantity
 msgid ""
diff --git a/addons/stock/models/product.py b/addons/stock/models/product.py
index 8d1b13b80b8..f25a143137b 100644
--- a/addons/stock/models/product.py
+++ b/addons/stock/models/product.py
@@ -837,6 +837,18 @@ class ProductTemplate(models.Model):
 
     def write(self, vals):
         self._sanitize_vals(vals)
+        if 'company_id' in vals and vals['company_id']:
+            products_changing_company = self.filtered(lambda product: product.company_id.id != vals['company_id'])
+            if products_changing_company:
+                # Forbid changing a product's company when quant(s) exist in another company.
+                quant = self.env['stock.quant'].sudo().search([
+                    ('product_id', 'in', products_changing_company.product_variant_ids.ids),
+                    ('company_id', '!=', vals['company_id']),
+                    ('quantity', '!=', 0),
+                ], order=None, limit=1)
+                if quant:
+                    raise UserError(_("This product's company cannot be changed as long as there are quantities of it belonging to another company."))
+
         if 'uom_id' in vals:
             new_uom = self.env['uom.uom'].browse(vals['uom_id'])
             updated = self.filtered(lambda template: template.uom_id != new_uom)
diff --git a/addons/stock/tests/test_product.py b/addons/stock/tests/test_product.py
index 415910daae7..08e713c6155 100644
--- a/addons/stock/tests/test_product.py
+++ b/addons/stock/tests/test_product.py
@@ -5,6 +5,7 @@
 # Copyright 2015 Camptocamp SA
 
 from odoo.addons.stock.tests.common2 import TestStockCommon
+from odoo.exceptions import UserError
 from odoo.tests.common import Form
 
 
@@ -102,6 +103,33 @@ class TestVirtualAvailable(TestStockCommon):
         self.product_3.active = False
         self.assertFalse(orderpoint.active)
 
+    def test_change_product_company(self):
+        """ Checks we can't change the product's company if this product has
+        quant in another company. """
+        company1 = self.env.ref('base.main_company')
+        company2 = self.env['res.company'].create({'name': 'Second Company'})
+        product = self.env['product.product'].create({
+            'name': 'Product [TEST - Change Company]',
+            'type': 'product',
+        })
+        # Creates a quant for productA in the first company.
+        self.env['stock.quant'].create({
+            'product_id': product.id,
+            'product_uom_id': self.uom_unit.id,
+            'location_id': self.location_1.id,
+            'quantity': 7,
+            'reserved_quantity': 0,
+        })
+        # Assigns a company: should be OK for company1 but should raise an error for company2.
+        product.company_id = company1.id
+        with self.assertRaises(UserError):
+            product.company_id = company2.id
+        # Checks we can assing company2 for the product once there is no more quant for it.
+        quant = self.env['stock.quant'].search([('product_id', '=', product.id)])
+        quant.quantity = 0
+        self.env['stock.quant']._unlink_zero_quants()
+        product.company_id = company2.id  # Should work this time.
+
     def test_search_qty_available(self):
         product = self.env['product.product'].create({
             'name': 'Brand new product',