diff --git a/movement/mover.py b/movement/mover.py
index 4e1e70b..bc6d4d4 100644
--- a/movement/mover.py
+++ b/movement/mover.py
@@ -93,7 +93,7 @@ def _create_functions(self):
             self.mesh.coordinates, name="Computational coordinates"
         )
         self.v = firedrake.Function(self.coord_space, name="Mesh velocity")
-        self.volume = firedrake.Cofunction(self.P0, name="Mesh volume")
+        self.volume = firedrake.Cofunction(self.P0.dual(), name="Mesh volume")
         self.volume.interpolate(ufl.CellVolume(self.mesh))
 
     def _convergence_message(self, iterations=None):