diff --git a/invesalius/data/styles.py b/invesalius/data/styles.py
index 7a7dc66..01f7408 100644
--- a/invesalius/data/styles.py
+++ b/invesalius/data/styles.py
@@ -486,7 +486,7 @@ class CrossInteractorStyle(DefaultInteractorStyle):
         x, y, z = self.viewer.get_coordinate_cursor(mouse_x, mouse_y, self.picker)
         self.viewer.UpdateSlicesPosition([x, y, z])
         # This "Set cross" message is needed to update the cross in the other slices
-        Publisher.sendMessage('Set cross focal point', position=[x, y, z, 0., 0., 0.])
+        Publisher.sendMessage('Set cross focal point', position=[x, y, z, None, None, None])
         Publisher.sendMessage('Update slice viewer')
 
     def OnScrollBar(self, *args, **kwargs):
@@ -494,7 +494,7 @@ class CrossInteractorStyle(DefaultInteractorStyle):
         # the actual orientation.
         x, y, z = self.viewer.cross.GetFocalPoint()
         self.viewer.UpdateSlicesPosition([x, y, z])
-        Publisher.sendMessage('Set cross focal point', position=[x, y, z, 0., 0., 0.])
+        Publisher.sendMessage('Set cross focal point', position=[x, y, z, None, None, None])
         Publisher.sendMessage('Update slice viewer')
 
 
--
libgit2 0.21.2