diff --git a/addons/website/models/ir_module_module.py b/addons/website/models/ir_module_module.py
index a563a9efa85..1073b384d81 100644
--- a/addons/website/models/ir_module_module.py
+++ b/addons/website/models/ir_module_module.py
@@ -75,6 +75,9 @@ class IrModuleModule(models.Model):
 
                     -> We want to upgrade every website using this theme.
         """
+        if request and request.context.get('apply_new_theme'):
+            self = self.with_context(apply_new_theme=True)
+
         for module in self:
             if module.name.startswith('theme_') and vals.get('state') == 'installed':
                 _logger.info('Module %s has been loaded as theme template (%s)' % (module.name, module.state))
@@ -207,7 +210,15 @@ class IrModuleModule(models.Model):
             for model_name in self._theme_model_names:
                 module._update_records(model_name, website)
 
-            self.env['theme.utils'].with_context(website_id=website.id)._post_copy(module)
+            if self._context.get('apply_new_theme'):
+                # Both the theme install and upgrade flow ends up here.
+                # The _post_copy() is supposed to be called only when the theme
+                # is installed for the first time on a website.
+                # It will basically select some header and footer template.
+                # We don't want the system to select again the theme footer or
+                # header template when that theme is updated later. It could
+                # erase the change the user made after the theme install.
+                self.env['theme.utils'].with_context(website_id=website.id)._post_copy(module)
 
     def _theme_unload(self, website):
         """
@@ -361,6 +372,8 @@ class IrModuleModule(models.Model):
         website.theme_id = self
 
         # this will install 'self' if it is not installed yet
+        if request:
+            request.update_context(apply_new_theme=True)
         self._theme_upgrade_upstream()
 
         active_todo = self.env['ir.actions.todo'].search([('state', '=', 'open')], limit=1)