diff --git a/gui/qt/main_window.py b/gui/qt/main_window.py
index 7ced30e8..b8dccc73 100644
--- a/gui/qt/main_window.py
+++ b/gui/qt/main_window.py
@@ -1060,6 +1060,7 @@ class ElectrumWindow(QMainWindow):
                 self.wallet.add_keypairs(tx, keypairs, password)
                 self.wallet.sign_transaction(tx, keypairs, password)
             except Exception as e:
+                traceback.print_exc(file=sys.stdout)
                 tx.error = str(e)
             return tx
 
diff --git a/lib/wallet.py b/lib/wallet.py
index f8eba63e..2d2ba93a 100644
--- a/lib/wallet.py
+++ b/lib/wallet.py
@@ -648,7 +648,7 @@ class Abstract_Wallet:
 
             # Insert the change output at a random position in the outputs
             posn = random.randint(0, len(outputs))
-            outputs[posn:posn] = [( change_addr,  change_amount)]
+            outputs[posn:posn] = [( 'address', change_addr,  change_amount)]
         return outputs
 
     def get_history(self, address):