diff --git a/cms/models/pluginmodel.py b/cms/models/pluginmodel.py
index 37f90d30e25..c684aaec2bc 100644
--- a/cms/models/pluginmodel.py
+++ b/cms/models/pluginmodel.py
@@ -238,7 +238,7 @@ def save(self, no_signals=False, *args, **kwargs):
                                                              placeholder_id=self.placeholder_id).count()
                 self.add_root(instance=self)
             return
-        super(CMSPlugin, self).save()
+        super(CMSPlugin, self).save(*args, **kwargs)
 
     def reload(self):
         return CMSPlugin.objects.get(pk=self.pk)
diff --git a/cms/utils/copy_plugins.py b/cms/utils/copy_plugins.py
index 6e316e511f8..ea9075cfdc3 100644
--- a/cms/utils/copy_plugins.py
+++ b/cms/utils/copy_plugins.py
@@ -29,7 +29,12 @@ def copy_plugins_to(old_plugins, to_placeholder,
         for idx, plugin in enumerate(new_plugins):
             if plugin.parent_id is None:
                 plugin.parent_id = parent_plugin_id
-                plugin.save()
+                # Always use update fields to avoid side-effects.
+                # In this case "plugin" has invalid values for internal fields
+                # like numchild.
+                # The invalid value is only in memory because the instance
+                # was never updated.
+                plugin.save(update_fields=['parent'])
                 new_plugins[idx] = plugin.move(parent_plugin, pos="last-child")
 
     plugins_ziplist = list(zip(new_plugins, old_plugins))