diff --git a/lib/browser/PayPro.js b/lib/browser/PayPro.js
index 16b23cb..b9ab061 100644
--- a/lib/browser/PayPro.js
+++ b/lib/browser/PayPro.js
@@ -38,7 +38,7 @@ PayPro.prototype.x509Sign = function(key) {
   key = rsa;
 
   var jsrsaSig = new KJUR.crypto.Signature({
-    alg: type.toUpperCase() + 'withRSA',
+    alg: type + 'withRSA',
     prov: 'cryptojs/jsrsa'
   });
 
@@ -60,7 +60,7 @@ PayPro.prototype.x509Verify = function(key) {
   var type = pki_type.split('+')[1].toUpperCase();
 
   var jsrsaSig = new KJUR.crypto.Signature({
-    alg: type.toUpperCase() + 'withRSA',
+    alg: type + 'withRSA',
     prov: 'cryptojs/jsrsa'
   });