diff --git a/contracts/token/ERC721/ERC721Basic.sol b/contracts/token/ERC721/ERC721Basic.sol
index 2a87b0597..2fe0b58b7 100644
--- a/contracts/token/ERC721/ERC721Basic.sol
+++ b/contracts/token/ERC721/ERC721Basic.sol
@@ -6,7 +6,7 @@ pragma solidity ^0.4.21;
  * @dev see https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
  */
 contract ERC721Basic {
-  event Transfer(address indexed _from, address indexed _to, uint256 _tokenId);
+  event Transfer(address indexed _from, address indexed _to, uint256 indexed _tokenId);
   event Approval(address indexed _owner, address indexed _approved, uint256 _tokenId);
   event ApprovalForAll(address indexed _owner, address indexed _operator, bool _approved);
 
diff --git a/package-lock.json b/package-lock.json
index 1a81b0f6f..679b4a2cc 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -12702,4 +12702,4 @@
       }
     }
   }
-}
+}
\ No newline at end of file