diff --git a/app/templates/element/search.php b/app/templates/element/search.php
index 5636a2289..16ceacb08 100644
--- a/app/templates/element/search.php
+++ b/app/templates/element/search.php
@@ -108,8 +108,8 @@
             // convert to a select
             $formParams['type'] = 'select';
             $formParams['options'] = $$key;
-            // XXX we don't have a use case yet to support empty
-            $formParams['empty'] = false;
+            // Allow empty so a filter doesn't require (eg) SOR
+            $formParams['empty'] = true;
           }
 
           print $this->Form->control($key, $formParams);