diff --git a/odoo/addons/base/models/ir_model.py b/odoo/addons/base/models/ir_model.py
index 45d5dae8301..d17116bd38f 100644
--- a/odoo/addons/base/models/ir_model.py
+++ b/odoo/addons/base/models/ir_model.py
@@ -623,12 +623,16 @@ class IrModelFields(models.Model):
                 continue
             model = self.env.get(field.model)
             is_model = model is not None
-            if is_model and tools.column_exists(self._cr, model._table, field.name) and \
-                    tools.table_kind(self._cr, model._table) == 'r':
-                self._cr.execute('ALTER TABLE "%s" DROP COLUMN "%s" CASCADE' % (model._table, field.name))
-            if field.state == 'manual' and field.ttype == 'many2many':
-                rel_name = field.relation_table or (is_model and model._fields[field.name].relation)
-                tables_to_drop.add(rel_name)
+            if field.store:
+                # TODO: Refactor this brol in master
+                if is_model and tools.column_exists(self._cr, model._table, field.name) and \
+                        tools.table_kind(self._cr, model._table) == 'r':
+                    self._cr.execute('ALTER TABLE "%s" DROP COLUMN "%s" CASCADE' % (
+                        model._table, field.name,
+                    ))
+                if field.state == 'manual' and field.ttype == 'many2many':
+                    rel_name = field.relation_table or (is_model and model._fields[field.name].relation)
+                    tables_to_drop.add(rel_name)
             if field.state == 'manual' and is_model:
                 model._pop_field(field.name)
             if field.translate:
diff --git a/odoo/addons/test_new_api/tests/test_new_fields.py b/odoo/addons/test_new_api/tests/test_new_fields.py
index 0712e088f78..3204b25bfe6 100644
--- a/odoo/addons/test_new_api/tests/test_new_fields.py
+++ b/odoo/addons/test_new_api/tests/test_new_fields.py
@@ -2037,6 +2037,18 @@ class TestX2many(common.TransactionCase):
         for line in lines:
             self.assertEqual(len(line.tags), 3)
 
+    def test_custom_m2m(self):
+        model_id = self.env['ir.model']._get_id('res.partner')
+        field = self.env['ir.model.fields'].create({
+            'name': 'x_foo',
+            'field_description': 'Foo',
+            'model_id': model_id,
+            'ttype': 'many2many',
+            'relation': 'res.country',
+            'store': False,
+        })
+        self.assertTrue(field.unlink())
+
 
 class TestHtmlField(common.TransactionCase):