diff --git a/EIPS/eip-721.md b/EIPS/eip-721.md
index 5bb490da..f296503e 100644
--- a/EIPS/eip-721.md
+++ b/EIPS/eip-721.md
@@ -51,13 +51,13 @@ interface ERC721 /* is ERC165 */ {
     ///  (`to` == 0). Exception: during contract creation, any number of NFTs
     ///  may be created and assigned without emitting Transfer. At the time of
     ///  any transfer, the approved address for that NFT (if any) is reset to none.
-    event Transfer(address indexed _from, address indexed _to, uint256 _tokenId);
+    event Transfer(address indexed _from, address indexed _to, uint256 indexed _tokenId);
 
     /// @dev This emits when the approved address for an NFT is changed or
     ///  reaffirmed. The zero address indicates there is no approved address.
     ///  When a Transfer event emits, this also indicates that the approved
     ///  address for that NFT (if any) is reset to none.
-    event Approval(address indexed _owner, address indexed _approved, uint256 _tokenId);
+    event Approval(address indexed _owner, address indexed _approved, uint256 indexed _tokenId);
 
     /// @dev This emits when an operator is enabled or disabled for an owner.
     ///  The operator can manage all NFTs of the owner.