diff --git a/src/controllers/api/inventoryController.ts b/src/controllers/api/inventoryController.ts
index 213102b3..cb855f16 100644
--- a/src/controllers/api/inventoryController.ts
+++ b/src/controllers/api/inventoryController.ts
@@ -109,7 +109,9 @@ export const inventoryController: RequestHandler = async (request, response) =>
             }
         }
 
-        getCalendarProgress(inventory); // handle year rollover; the client expects to receive an inventory with an up-to-date CalendarProgress
+        if (inventory.CalendarProgress) {
+            getCalendarProgress(inventory); // handle year rollover; the client expects to receive an inventory with an up-to-date CalendarProgress
+        }
 
         cleanupInventory(inventory);