diff --git a/invokeai/app/services/item_storage/item_storage_memory.py b/invokeai/app/services/item_storage/item_storage_memory.py
index 0ab495271c..d8dd0e0664 100644
--- a/invokeai/app/services/item_storage/item_storage_memory.py
+++ b/invokeai/app/services/item_storage/item_storage_memory.py
@@ -10,7 +10,7 @@ from invokeai.app.services.item_storage.item_storage_common import ItemNotFoundE
 T = TypeVar("T", bound=BaseModel)
 
 
-class ItemStorageMemory(ItemStorageABC, Generic[T]):
+class ItemStorageMemory(ItemStorageABC[T], Generic[T]):
     """
     Provides a simple in-memory storage for items, with a maximum number of items to store.
     The storage uses the LRU strategy to evict items from storage when the max has been reached.
diff --git a/tests/test_item_storage_memory.py b/tests/test_item_storage_memory.py
index 23ce1ec3a8..15758094d7 100644
--- a/tests/test_item_storage_memory.py
+++ b/tests/test_item_storage_memory.py
@@ -18,19 +18,19 @@ def item_storage_memory():
 
 
 def test_item_storage_memory_initializes():
-    item_storage_memory = ItemStorageMemory()
+    item_storage_memory = ItemStorageMemory[MockItemModel]()
     assert item_storage_memory._items == {}
     assert item_storage_memory._id_field == "id"
     assert item_storage_memory._max_items == 10
 
-    item_storage_memory = ItemStorageMemory(id_field="bananas", max_items=20)
+    item_storage_memory = ItemStorageMemory[MockItemModel](id_field="bananas", max_items=20)
     assert item_storage_memory._id_field == "bananas"
     assert item_storage_memory._max_items == 20
 
     with pytest.raises(ValueError, match=re.escape("max_items must be at least 1")):
-        item_storage_memory = ItemStorageMemory(max_items=0)
+        item_storage_memory = ItemStorageMemory[MockItemModel](max_items=0)
     with pytest.raises(ValueError, match=re.escape("id_field must not be empty")):
-        item_storage_memory = ItemStorageMemory(id_field="")
+        item_storage_memory = ItemStorageMemory[MockItemModel](id_field="")
 
 
 def test_item_storage_memory_sets(item_storage_memory: ItemStorageMemory[MockItemModel]):
@@ -74,7 +74,7 @@ def test_item_storage_memory_deletes(item_storage_memory: ItemStorageMemory[Mock
 
 
 def test_item_storage_memory_respects_max():
-    item_storage_memory = ItemStorageMemory(max_items=3)
+    item_storage_memory = ItemStorageMemory[MockItemModel](max_items=3)
     for i in range(10):
         item_storage_memory.set(MockItemModel(id=str(i), value=i))
     assert item_storage_memory._items == {