diff --git a/src/Filtering/Filter.coffee b/src/Filtering/Filter.coffee
index 8ac6e18c9..98cdbf11c 100644
--- a/src/Filtering/Filter.coffee
+++ b/src/Filtering/Filter.coffee
@@ -5,6 +5,11 @@ Filter =
 
     for key of Config.filter
       @filters[key] = []
+      if Conf[key] is undefined
+        # XXX hopefully tmp fix for the rare people getting this mysterious error:
+        #   "Filter" initialization crashed. TypeError: Cannot call method 'split' of undefined
+        $.delete key
+        continue
       for filter in Conf[key].split '\n'
         continue if filter[0] is '#'