diff --git a/src/ifcopenshell-python/ifcopenshell/api/owner/add_application.py b/src/ifcopenshell-python/ifcopenshell/api/owner/add_application.py
index 3fc9234c85..5c86ab78d3 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/owner/add_application.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/owner/add_application.py
@@ -17,7 +17,7 @@
 # along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
 
 import ifcopenshell.api
-from typing import Optional, Any
+from typing import Optional, Any, Union
 
 
 def add_application(
@@ -53,33 +53,35 @@ def add_application(
     """
     usecase = Usecase()
     usecase.file = file
-    usecase.settings = {
-        "application_developer": application_developer,
-        "version": version or ifcopenshell.version,
-        "application_full_name": application_full_name,
-        "application_identifier": application_identifier,
-    }
-    return usecase.execute()
+    return usecase.execute(
+        application_developer,
+        version or ifcopenshell.version,
+        application_full_name,
+        application_identifier,
+    )
 
 
 class Usecase:
     file: ifcopenshell.file
-    settings: dict[str, Any]
 
-    def execute(self):
-        if not self.settings["application_developer"]:
-            self.settings["application_developer"] = self.create_application_organisation()
+    def execute(
+        self,
+        application_developer: Union[ifcopenshell.entity_instance, None],
+        version: str,
+        application_full_name: str,
+        application_identifier: str,
+    ) -> ifcopenshell.entity_instance:
+        if not application_developer:
+            application_developer = self.create_application_organisation()
         return self.file.create_entity(
             "IfcApplication",
-            **{
-                "ApplicationDeveloper": self.settings["application_developer"],
-                "Version": self.settings["version"],
-                "ApplicationFullName": self.settings["application_full_name"],
-                "ApplicationIdentifier": self.settings["application_identifier"],
-            },
+            ApplicationDeveloper=application_developer,
+            Version=version,
+            ApplicationFullName=application_full_name,
+            ApplicationIdentifier=application_identifier,
         )
 
-    def create_application_organisation(self):
+    def create_application_organisation(self) -> ifcopenshell.entity_instance:
         result = self.file.create_entity(
             "IfcOrganization",
             **{
@@ -100,5 +102,6 @@ class Usecase:
                 ],
             },
         )
+        # 0 IfcOrganization.Identification / Id (IFC2X3).
         result[0] = "IfcOpenShell"
         return result