diff --git a/gui/qt/history_list.py b/gui/qt/history_list.py
index 142d9828..fcd4deb4 100644
--- a/gui/qt/history_list.py
+++ b/gui/qt/history_list.py
@@ -58,15 +58,15 @@ class HistoryList(MyTreeWidget, AcceptFileDragDrop):
         self.setColumnHidden(1, True)
 
     def refresh_headers(self):
-        headers = ['', '', _('Date'), _('Description') , _('Amount'), _('Balance')]
+        headers = ['', '', _('Date'), _('Description'), _('Amount'), _('Balance')]
         fx = self.parent.fx
         if fx and fx.show_history():
             headers.extend(['%s '%fx.ccy + _('Value')])
             headers.extend(['%s '%fx.ccy + _('Acquisition price')])
             headers.extend(['%s '%fx.ccy + _('Capital Gains')])
-            fiat_value_column = 6
-            if fiat_value_column not in self.editable_columns:
-                self.editable_columns.extend([fiat_value_column])
+            self.editable_columns |= {6}
+        else:
+            self.editable_columns -= {6}
         self.update_headers(headers)
 
     def get_domain(self):
diff --git a/gui/qt/util.py b/gui/qt/util.py
index 5dbda84a..c0bdf62e 100644
--- a/gui/qt/util.py
+++ b/gui/qt/util.py
@@ -389,7 +389,9 @@ class MyTreeWidget(QTreeWidget):
         self.editor = None
         self.pending_update = False
         if editable_columns is None:
-            editable_columns = [stretch_column]
+            editable_columns = {stretch_column}
+        else:
+            editable_columns = set(editable_columns)
         self.editable_columns = editable_columns
         self.setItemDelegate(ElectrumItemDelegate(self))
         self.itemDoubleClicked.connect(self.on_doubleclick)