diff --git a/contracts/token/ERC721/ERC721Basic.sol b/contracts/token/ERC721/ERC721Basic.sol
index 2fe0b58b7..93c0e2588 100644
--- a/contracts/token/ERC721/ERC721Basic.sol
+++ b/contracts/token/ERC721/ERC721Basic.sol
@@ -7,7 +7,7 @@ pragma solidity ^0.4.21;
  */
 contract ERC721Basic {
   event Transfer(address indexed _from, address indexed _to, uint256 indexed _tokenId);
-  event Approval(address indexed _owner, address indexed _approved, uint256 _tokenId);
+  event Approval(address indexed _owner, address indexed _approved, uint256 indexed _tokenId);
   event ApprovalForAll(address indexed _owner, address indexed _operator, bool _approved);
 
   function balanceOf(address _owner) public view returns (uint256 _balance);