diff --git a/lib/private_api.js b/lib/private_api.js
index d678f7c..683fe1c 100644
--- a/lib/private_api.js
+++ b/lib/private_api.js
@@ -82,8 +82,8 @@ TradeApi.prototype.withdrawHistory = function(options){
 
 TradeApi.prototype.trade = function(currency_pair, action, price, amount, options){
     return this.query('trade', {
-        currency_pair : currency_pair,
-        action : action,
+        currency_pair : currency_pair.toLowerCase(),
+        action : action.toLowerCase(),
         price : price,
         amount : amount
     }, options)
@@ -97,7 +97,7 @@ TradeApi.prototype.cancelOrder = function(order_id, options){
 
 TradeApi.prototype.withdraw = function(currency, address, amount, options){
     return this.query('withdraw', {
-        currency : currency,
+        currency : currency.toLowerCase(),
         address : address,
         amount : amount,
     }, options)