diff --git a/lib/Query/Common/CriterionVisitor/Field/FieldEmpty.php b/lib/Query/Common/CriterionVisitor/Field/FieldEmpty.php
index f363f5f94..12b594159 100644
--- a/lib/Query/Common/CriterionVisitor/Field/FieldEmpty.php
+++ b/lib/Query/Common/CriterionVisitor/Field/FieldEmpty.php
@@ -77,6 +77,6 @@ public function visit(Criterion $criterion, CriterionVisitor $subVisitor = null)
             }
         }
 
-        return '(' . implode(' OR ', $queries) . ')';
+        return '(' . implode(' OR ', array_unique($queries)) . ')';
     }
 }