diff --git a/src/festim/hydrogen_transport_problem.py b/src/festim/hydrogen_transport_problem.py
index 14d9c35b4..ee37837d2 100644
--- a/src/festim/hydrogen_transport_problem.py
+++ b/src/festim/hydrogen_transport_problem.py
@@ -646,6 +646,7 @@ def assign_functions_to_species(self):
             spe.sub_function_space = self.function_space.sub(idx)
             spe.sub_function = self.u.sub(idx)  # TODO add this to discontinuous class
             spe.post_processing_solution = self.u.sub(idx).collapse()
+            spe.post_processing_solution.name = spe.name
             spe.collapsed_function_space, spe.map_sub_to_main_solution = (
                 self.function_space.sub(idx).collapse()
             )