diff --git a/EDMarketConnector.py b/EDMarketConnector.py
index 6b65c0ae..7d13346e 100755
--- a/EDMarketConnector.py
+++ b/EDMarketConnector.py
@@ -1054,6 +1054,7 @@ if __name__ == "__main__":
     if not ui_scaling:
         ui_scaling = '0.0'
         config.set('ui_scaling', ui_scaling)
+    theme.default_ui_scale = root.tk.call('tk', 'scaling')
     if ui_scaling != '0.0':
         root.tk.call('tk', 'scaling', float(ui_scaling))
     app = AppWindow(root)
diff --git a/theme.py b/theme.py
index ab6d89e9..f1a97721 100644
--- a/theme.py
+++ b/theme.py
@@ -115,6 +115,7 @@ class _Theme(object):
         self.widgets_pair = []
         self.defaults = {}
         self.current = {}
+        self.default_ui_scale = None  # None == not yet known
 
     def register(self, widget):
         # Note widget and children for later application of a theme. Note if the widget has explicit fg or bg attributes.