diff --git a/plugins/OptionalManager/ContentDbPlugin.py b/plugins/OptionalManager/ContentDbPlugin.py
index 997092d0..df575603 100644
--- a/plugins/OptionalManager/ContentDbPlugin.py
+++ b/plugins/OptionalManager/ContentDbPlugin.py
@@ -235,6 +235,8 @@ class ContentDbPlugin(object):
         for site in self.sites.values():
             if not site.content_manager.has_optional_files:
                 continue
+            if not site.settings["serving"]:
+                continue
             has_updated_hashfield = next((
                 peer
                 for peer in site.peers.itervalues()