diff --git a/contracts/token/StandardToken.sol b/contracts/token/StandardToken.sol
index 5daf15d7f..213989655 100644
--- a/contracts/token/StandardToken.sol
+++ b/contracts/token/StandardToken.sol
@@ -62,10 +62,14 @@ contract StandardToken is ERC20, BasicToken {
   }
 
   /**
+   * @dev Increase the amount of tokens that an owner allowed to a spender.
+   *
    * approve should be called when allowed[_spender] == 0. To increment
    * allowed value is better to use this function to avoid 2 calls (and wait until
    * the first transaction is mined)
    * From MonolithDAO Token.sol
+   * @param _spender The address which will spend the funds.
+   * @param _addedValue The amount of tokens to increase the allowance by.
    */
   function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
     allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
@@ -73,6 +77,16 @@ contract StandardToken is ERC20, BasicToken {
     return true;
   }
 
+  /**
+   * @dev Decrease the amount of tokens that an owner allowed to a spender.
+   *
+   * approve should be called when allowed[_spender] == 0. To decrement
+   * allowed value is better to use this function to avoid 2 calls (and wait until
+   * the first transaction is mined)
+   * From MonolithDAO Token.sol
+   * @param _spender The address which will spend the funds.
+   * @param _subtractedValue The amount of tokens to decrease the allowance by.
+   */
   function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
     uint oldValue = allowed[msg.sender][_spender];
     if (_subtractedValue > oldValue) {