diff --git a/lib/paygate/profile.rb b/lib/paygate/profile.rb
index 303238c..6bb05e2 100644
--- a/lib/paygate/profile.rb
+++ b/lib/paygate/profile.rb
@@ -19,7 +19,8 @@ def purchase(currency, amount)
       params = { profile_no: profile_no,
                  mid: member.mid,
                  goodcurrency: currency,
-                 unitprice: amount }.delete_if { |_, v| v.blank? }
+                 unitprice: amount }
+      params.compact!
 
       # Make request
       uri = URI(PURCHASE_URL)
diff --git a/lib/paygate/transaction.rb b/lib/paygate/transaction.rb
index 0e9fee8..e956b16 100644
--- a/lib/paygate/transaction.rb
+++ b/lib/paygate/transaction.rb
@@ -26,7 +26,7 @@ def refund(options = {})
       params.merge!(options.slice(:amount))
       params[:amount] ||= FULL_AMOUNT_IDENTIFIER
       params[:mb_serial_no] = options[:order_id]
-      params.delete_if { |_, v| v.blank? }
+      params.compact!
 
       # Make request
       uri = URI(self.class.refund_api_url)