diff --git a/lib/cartopy/mpl/contour.py b/lib/cartopy/mpl/contour.py
index 47f2f2401..3e4a3843f 100644
--- a/lib/cartopy/mpl/contour.py
+++ b/lib/cartopy/mpl/contour.py
@@ -101,7 +101,7 @@ def clabel(self, *args, **kwargs):
             # collection's paths.
             paths = self.get_paths()
             new_paths = [col_to_data.transform_path(path) for path in paths]
-            paths[:] = new_paths
+            self.set_paths(new_paths)
 
             # The collection will now be referenced in axes projection
             # coordinates.