diff --git a/libs/cartesiandomain/add_supers_at_domain_top.hpp b/libs/cartesiandomain/add_supers_at_domain_top.hpp
index 5a0ab8266..5c0934c23 100644
--- a/libs/cartesiandomain/add_supers_at_domain_top.hpp
+++ b/libs/cartesiandomain/add_supers_at_domain_top.hpp
@@ -29,6 +29,7 @@
 #include "../kokkosaliases.hpp"
 #include "cartesiandomain/cartesianmaps.hpp"
 #include "gridboxes/sortsupers.hpp"
+#include "initialise/optional_config_params.hpp"
 
 struct AddSupersAtDomainTop {
   double coord3lim; /**< gridboxes with upper bound > coord3lim get new super-droplets */
diff --git a/libs/initialise/optional_config_params.cpp b/libs/initialise/optional_config_params.cpp
index 2d328329f..2bc759ec3 100644
--- a/libs/initialise/optional_config_params.cpp
+++ b/libs/initialise/optional_config_params.cpp
@@ -177,7 +177,7 @@ void OptionalConfigParams::CvodeDynamicsParams::print_params() const {
             << "\n---------------------------------------------------------\n";
 }
 
-void OptionalConfigParams::AddSupersAtDomainTopParams : set_params(const YAML::Node &config) {
+void OptionalConfigParams::AddSupersAtDomainTopParams::set_params(const YAML::Node &config) {
   const YAML::Node yaml = config["boundary_conditions"];
 
   COORD3LIM = yaml["COORD3LIM"].as<double>();
diff --git a/libs/initialise/optional_config_params.hpp b/libs/initialise/optional_config_params.hpp
index 120e14829..c3c6a42e2 100644
--- a/libs/initialise/optional_config_params.hpp
+++ b/libs/initialise/optional_config_params.hpp
@@ -54,6 +54,8 @@ struct OptionalConfigParams {
 
   void set_coupled_dynamics(const YAML::Node& config);
 
+  void set_boundary_conditions(const YAML::Node& config);
+
   /*** Super-Droplet Microphysics Parameters ***/
   struct CondensationParams {
     void set_params(const YAML::Node& config);