diff --git a/src/controllers/api/completeCalendarEventController.ts b/src/controllers/api/completeCalendarEventController.ts
index 3b1bf106..20c8abb3 100644
--- a/src/controllers/api/completeCalendarEventController.ts
+++ b/src/controllers/api/completeCalendarEventController.ts
@@ -21,6 +21,8 @@ export const completeCalendarEventController: RequestHandler = async (req, res)
                     if (selection.type == "CET_REWARD") {
                         inventoryChanges = (await handleStoreItemAcquisition(selection.reward!, inventory))
                             .InventoryChanges;
+                    } else if (selection.type == "CET_UPGRADE") {
+                        calendarProgress.YearProgress.Upgrades.push(selection.upgrade!);
                     } else if (selection.type != "CET_PLOT") {
                         throw new Error(`unexpected selection type: ${selection.type}`);
                     }