diff --git a/src/module/actor/actor-sheet.ts b/src/module/actor/actor-sheet.ts
index 94dcafcd..4b2c69d8 100644
--- a/src/module/actor/actor-sheet.ts
+++ b/src/module/actor/actor-sheet.ts
@@ -110,7 +110,7 @@ export class DS4ActorSheet extends ActorSheet<DS4ActorDataType, DS4Actor, DS4Ite
         const el: HTMLFormElement = $(ev.currentTarget).get(0);
         const id = $(ev.currentTarget).parents(".item").data("itemId");
         const item = duplicate(this.actor.getOwnedItem(id)); // getOwnedItem is typed incorrectly, it actually returns a ItemData<DS4ItemDataType>, not an Item
-        const property: string = $(ev.currentTarget).data("property");
+        const property: string | undefined = $(ev.currentTarget).data("property");
 
         // Early return:
         // Disabled => do nothing