diff --git a/app/models/manager_refresh/inventory_collection.rb b/app/models/manager_refresh/inventory_collection.rb
index 4ceef9e5478..0d7a7d1ca86 100644
--- a/app/models/manager_refresh/inventory_collection.rb
+++ b/app/models/manager_refresh/inventory_collection.rb
@@ -378,6 +378,10 @@ def data_collection_finalized?
       data_collection_finalized
     end
 
+    def supports_sti?
+      @supports_sti_cache ||= model_class.column_names.include?("type")
+    end
+
     def <<(inventory_object)
       unless data_index[inventory_object.manager_uuid]
         data_index[inventory_object.manager_uuid] = inventory_object
@@ -476,6 +480,13 @@ def new_inventory_object(hash)
     def build(hash)
       hash = hash.merge(builder_params)
       inventory_object = new_inventory_object(hash)
+
+      uuid = inventory_object.manager_uuid
+      # Each InventoryObject must be able to build an UUID, return nil if it can't
+      return nil if uuid.blank?
+      # Return existing InventoryObject if we have it
+      return data_index[uuid] if data_index[uuid]
+      # Store new InventoryObject and return it
       push(inventory_object)
       inventory_object
     end