diff --git a/src/textual/_layout.py b/src/textual/_layout.py
index a0100b4b24..312f8c9fe5 100644
--- a/src/textual/_layout.py
+++ b/src/textual/_layout.py
@@ -161,7 +161,7 @@ def get_content_width(self, widget: Widget, container: Size, viewport: Size) ->
             width = 0
         else:
             arrangement = widget._arrange(Size(0, 0))
-            return arrangement.spatial_map.total_region.right
+            return arrangement.total_region.right
         return width
 
     def get_content_height(