diff --git a/panels/exclude.py b/panels/exclude.py
index ee026ebd..f0d92f73 100644
--- a/panels/exclude.py
+++ b/panels/exclude.py
@@ -44,7 +44,7 @@ class Panel(ScreenPanel):
             else:
                 grid.attach(self.labels['map'], 0, 2, 1, 1)
                 grid.attach(scroll, 1, 2, 1, 1)
-                scroll.set_size_request((self._screen.width - 30) // 2, -1)
+                scroll.set_size_request(self._gtk.content_width / 2 - 30, -1)
         else:
             grid.attach(scroll, 0, 2, 2, 1)
             scroll.set_size_request(self._gtk.content_width - 30, -1)