diff --git a/src/classes/DataBoard.coffee b/src/classes/DataBoard.coffee
index 26aa24414..7429a370e 100644
--- a/src/classes/DataBoard.coffee
+++ b/src/classes/DataBoard.coffee
@@ -109,6 +109,9 @@ class DataBoard
     val or defaultValue
 
   clean: ->
+    # XXX not yet multisite ready
+    return unless Site.software is 'yotsuba'
+
     for boardID, val of @data.boards
       @deleteIfEmpty {boardID}