diff --git a/Testnet/NonFungibleToken-Ticket/NonFungibleToken/NonFungibleToken.cs b/Testnet/NonFungibleToken-Ticket/NonFungibleToken/NonFungibleToken.cs
index 4015af9e..71ec7421 100644
--- a/Testnet/NonFungibleToken-Ticket/NonFungibleToken/NonFungibleToken.cs
+++ b/Testnet/NonFungibleToken-Ticket/NonFungibleToken/NonFungibleToken.cs
@@ -183,8 +183,8 @@ public NonFungibleToken(ISmartContractState state, string name, string symbol, b
     public void MarkAsUsed(UInt256 tokenId)
     {
         EnsureOwnerOnly();
-        this.SetIsUsed(tokenId, true);
-        this.LogMarkAsUsed(tokenId);
+        SetIsUsed(tokenId, true);
+        LogMarkAsUsed(tokenId);
     }
 
     /// <summary>
@@ -194,7 +194,7 @@ public void MarkAsUsed(UInt256 tokenId)
     /// <returns></returns>
     public bool IsUsed(UInt256 tokenId)
     {
-        return this.GetIsUsed(tokenId);
+        return GetIsUsed(tokenId);
     }
 
     /// <summary>