diff --git a/spine_engine/load_project_items.py b/spine_engine/load_project_items.py
index 849d5e4e..153c6f22 100644
--- a/spine_engine/load_project_items.py
+++ b/spine_engine/load_project_items.py
@@ -9,14 +9,8 @@
 # Public License for more details. You should have received a copy of the GNU Lesser General Public License along with
 # this program. If not, see <http://www.gnu.org/licenses/>.
 ######################################################################################################################
-
-"""
-Functions to load project item modules.
-
-"""
-import pathlib
+""" Functions to load project item modules. """
 import importlib
-import importlib.util
 
 
 def load_item_specification_factories(items_package_name):
@@ -30,21 +24,7 @@ def load_item_specification_factories(items_package_name):
         dict: a map from item type to specification factory
     """
     items = importlib.import_module(items_package_name)
-    items_root = pathlib.Path(items.__file__).parent
-    factories = dict()
-    for child in items_root.iterdir():
-        if child.is_dir() and (
-            child.joinpath("specification_factory.py").exists()
-            or child.is_dir()
-            and child.joinpath("specification_factory.pyc").exists()
-        ):
-            spec = importlib.util.find_spec(f"{items_package_name}.{child.stem}.specification_factory")
-            m = importlib.util.module_from_spec(spec)
-            spec.loader.exec_module(m)
-            if hasattr(m, "SpecificationFactory"):
-                item_type = m.SpecificationFactory.item_type()
-                factories[item_type] = m.SpecificationFactory
-    return factories
+    return items.item_specification_factories()
 
 
 def load_executable_item_classes(items_package_name):
@@ -58,19 +38,4 @@ def load_executable_item_classes(items_package_name):
         dict: a map from item type to the executable item class
     """
     items = importlib.import_module(items_package_name)
-    items_root = pathlib.Path(items.__file__).parent
-    classes = dict()
-    for child in items_root.iterdir():
-        if (
-            child.is_dir()
-            and child.joinpath("executable_item.py").exists()
-            or (child.is_dir() and child.joinpath("executable_item.pyc").exists())
-        ):
-            spec = importlib.util.find_spec(f"{items_package_name}.{child.stem}.executable_item")
-            m = importlib.util.module_from_spec(spec)
-            spec.loader.exec_module(m)
-            if hasattr(m, "ExecutableItem"):
-                item_class = m.ExecutableItem
-                item_type = item_class.item_type()
-                classes[item_type] = item_class
-    return classes
+    return items.executable_items()
diff --git a/tests/mock_project_items/items_module/__init__.py b/tests/mock_project_items/items_module/__init__.py
index e69de29b..bd55ec1d 100644
--- a/tests/mock_project_items/items_module/__init__.py
+++ b/tests/mock_project_items/items_module/__init__.py
@@ -0,0 +1,10 @@
+def item_specification_factories():
+    from .test_item.specification_factory import SpecificationFactory
+
+    return {"TestItem": SpecificationFactory}
+
+
+def executable_items():
+    from .test_item.executable_item import ExecutableItem
+
+    return {"TestItem": ExecutableItem}