diff --git a/lib/pagseguro/transaction/serializer.rb b/lib/pagseguro/transaction/serializer.rb
index c37395c..4a14641 100644
--- a/lib/pagseguro/transaction/serializer.rb
+++ b/lib/pagseguro/transaction/serializer.rb
@@ -72,10 +72,10 @@ def serialize_creditor(data)
           intermediation_fee_amount: BigDecimal(xml.css("creditorFees > intermediationFeeAmount").text.to_f.to_s),
           installment_fee_amount: BigDecimal(xml.css("creditorFees > installmentFeeAmount").text.to_f.to_s),
         }
-        operationalFeeAmount = xml.css("creditorFees > operationalFeeAmount").text
-        data[:creditor_fees].merge!(operational_fee_amount: BigDecimal(operationalFeeAmount)) if operationalFeeAmount.present?
-        commissionFeeAmount = xml.css("creditorFees > commissionFeeAmount").text
-        data[:creditor_fees].merge!(commission_fee_amount: BigDecimal(commissionFeeAmount)) if commissionFeeAmount.present?
+        operational_fee_amount = xml.css("creditorFees > operationalFeeAmount").text
+        data[:creditor_fees].merge!(operational_fee_amount: BigDecimal(operational_fee_amount)) if operational_fee_amount.present?
+        commission_fee_amount = xml.css("creditorFees > commissionFeeAmount").text
+        data[:creditor_fees].merge!(commission_fee_amount: BigDecimal(commission_fee_amount)) if commission_fee_amount.present?
         efrete = xml.css("creditorFees > efrete").text
         data[:creditor_fees].merge!(efrete: BigDecimal(efrete)) if efrete.present?
       end