diff --git a/generate_parameter_library_py/generate_parameter_library_py/jinja_templates/python/parameter_library_header b/generate_parameter_library_py/generate_parameter_library_py/jinja_templates/python/parameter_library_header
index 2247da3..0bfb5b5 100644
--- a/generate_parameter_library_py/generate_parameter_library_py/jinja_templates/python/parameter_library_header
+++ b/generate_parameter_library_py/generate_parameter_library_py/jinja_templates/python/parameter_library_header
@@ -54,8 +54,7 @@ stamp_ = Time()
         def is_old(self, other_param):
             return self.params_.stamp_ != other_param.stamp_
 
-        @staticmethod
-        def unpack_parameter_dict(namespace: str, parameter_dict: dict):
+        def unpack_parameter_dict(self, namespace: str, parameter_dict: dict):
             """
             Flatten a parameter dictionary recursively.
 
@@ -68,7 +67,7 @@ stamp_ = Time()
                 full_param_name = namespace + param_name
                 # Unroll nested parameters
                 if isinstance(param_value, dict):
-                    nested_params = unpack_parameter_dict(
+                    nested_params = self.unpack_parameter_dict(
                             namespace=full_param_name + rclpy.parameter.PARAMETER_SEPARATOR_STRING,
                             parameter_dict=param_value)
                     parameters.extend(nested_params)
@@ -77,7 +76,7 @@ stamp_ = Time()
             return parameters
 
         def set_params_from_dict(self, param_dict):
-            params_to_set = unpack_parameter_dict('', param_dict)
+            params_to_set = self.unpack_parameter_dict('', param_dict)
             self.update(params_to_set)
 
         def refresh_dynamic_parameters(self):