diff --git a/Lib9c/Model/Item/Equipment.cs b/Lib9c/Model/Item/Equipment.cs
index e70f1eeac3..3e0493f98a 100644
--- a/Lib9c/Model/Item/Equipment.cs
+++ b/Lib9c/Model/Item/Equipment.cs
@@ -130,7 +130,10 @@ public override IValue Serialize()
                 dict = dict.SetItem(MadeWithMimisbrunnrRecipeKey, MadeWithMimisbrunnrRecipe.Serialize());
             }
 
-            dict = dict.SetItem(EquipmentExpKey, Exp.Serialize());
+            if (Exp > 0)
+            {
+                dict = dict.SetItem(EquipmentExpKey, Exp.Serialize());
+            }
 
             return dict;
 #pragma warning restore LAA1002