diff --git a/addons/mail/models/mail_activity.py b/addons/mail/models/mail_activity.py
index c8085802faf..8fc502ee6de 100644
--- a/addons/mail/models/mail_activity.py
+++ b/addons/mail/models/mail_activity.py
@@ -10,6 +10,7 @@ import pytz
 from odoo import api, exceptions, fields, models, _
 
 from odoo.tools.misc import clean_context
+from odoo.addons.base.models.ir_model import MODULE_UNINSTALL_FLAG
 
 _logger = logging.getLogger(__name__)
 
@@ -91,7 +92,7 @@ class MailActivityType(models.Model):
             activity_type.initial_res_model_id = activity_type.res_model_id
 
     def unlink(self):
-        if any(self.get_external_id().values()):
+        if any(self.get_external_id().values()) and not self._context.get(MODULE_UNINSTALL_FLAG):
             raise exceptions.ValidationError("You can not delete activity type that are used as master data.")
         return super(MailActivityType, self).unlink()
 
diff --git a/addons/mail/models/mail_channel.py b/addons/mail/models/mail_channel.py
index 255b601ddbd..a2f211c3fa0 100644
--- a/addons/mail/models/mail_channel.py
+++ b/addons/mail/models/mail_channel.py
@@ -11,6 +11,7 @@ from odoo import _, api, fields, models, modules, tools
 from odoo.exceptions import UserError, ValidationError
 from odoo.osv import expression
 from odoo.tools import ormcache, formataddr
+from odoo.addons.base.models.ir_model import MODULE_UNINSTALL_FLAG
 
 MODERATION_FIELDS = ['moderation', 'moderator_ids', 'moderation_ids', 'moderation_notify', 'moderation_notify_msg', 'moderation_guidelines', 'moderation_guidelines_msg']
 _logger = logging.getLogger(__name__)
@@ -227,7 +228,7 @@ class Channel(models.Model):
             all_emp_group = self.env.ref('mail.channel_all_employees')
         except ValueError:
             all_emp_group = None
-        if all_emp_group and all_emp_group in self:
+        if all_emp_group and all_emp_group in self and not self._context.get(MODULE_UNINSTALL_FLAG):
             raise UserError(_('You cannot delete those groups, as the Whole Company group is required by other modules.'))
         res = super(Channel, self).unlink()
         # Cascade-delete mail aliases as well, as they should not exist without the mail.channel.