diff --git a/ProcessLib/BoundaryCondition/NeumannBoundaryConditionLocalAssembler.h b/ProcessLib/BoundaryCondition/NeumannBoundaryConditionLocalAssembler.h
index 23f74a4c4e70fb9870392f11e9fc07fce3d563cd..529313734041734872b3440f6a7e5bf55632ec94 100644
--- a/ProcessLib/BoundaryCondition/NeumannBoundaryConditionLocalAssembler.h
+++ b/ProcessLib/BoundaryCondition/NeumannBoundaryConditionLocalAssembler.h
@@ -33,7 +33,7 @@ public:
     NeumannBoundaryConditionLocalAssembler(
         MeshLib::Element const& e,
         std::size_t const local_matrix_size,
-        bool is_axially_symmetric,
+        bool const is_axially_symmetric,
         unsigned const integration_order,
         Parameter<double> const& neumann_bc_parameter)
         : Base(e, is_axially_symmetric, integration_order),