diff --git a/src/models.rs b/src/models.rs
index 8d74f87..6fe80b4 100644
--- a/src/models.rs
+++ b/src/models.rs
@@ -70,6 +70,7 @@ pub struct ItemClass {
 #[derive(Debug, Insertable, Deserialize, AsChangeset)]
 #[diesel(table_name = item_classes)]
 #[diesel(check_for_backend(diesel::pg::Pg))]
+#[diesel(treat_none_as_null = true)]
 pub struct NewItemClass {
     pub name: String,
     pub r#type: ItemClassType,