diff --git a/lib/mergeDeep.js b/lib/mergeDeep.js
index a685a048..054a5b34 100644
--- a/lib/mergeDeep.js
+++ b/lib/mergeDeep.js
@@ -378,5 +378,4 @@ class MergeDeep {
   }
 }
 MergeDeep.NAME_FIELDS = NAME_FIELDS
-MergeDeep.NAME_FIELDS = NAME_FIELDS
 module.exports = MergeDeep