diff --git a/gui/qt/main_window.py b/gui/qt/main_window.py
index 2f2e3dd2a..49c6b98f1 100644
--- a/gui/qt/main_window.py
+++ b/gui/qt/main_window.py
@@ -952,7 +952,7 @@ class ElectrumWindow(QMainWindow):
                 tx = self.wallet.make_unsigned_transaction(outputs, fee, coins = self.get_coins())
                 self.not_enough_funds = (tx is None)
                 if not is_fee:
-                    fee = tx.get_fee() if tx else None
+                    fee = self.wallet.get_tx_fee(tx) if tx else None
                     self.fee_e.setAmount(fee)
 
         self.payto_e.textChanged.connect(lambda:text_edited(False))
diff --git a/lib/wallet.py b/lib/wallet.py
index 502093278..d02908937 100644
--- a/lib/wallet.py
+++ b/lib/wallet.py
@@ -693,6 +693,10 @@ class Abstract_Wallet(object):
 
         return default_label
 
+    def get_tx_fee(self, tx):
+        # this method can be overloaded
+        return tx.get_fee()
+
     def estimated_fee(self, tx):
         estimated_size = len(tx.serialize(-1))/2
         fee = int(self.fee_per_kb*estimated_size/1000.)