diff --git a/src/components/library/UpdateChecker.tsx b/src/components/library/UpdateChecker.tsx
index 678cb94a..b7310b56 100644
--- a/src/components/library/UpdateChecker.tsx
+++ b/src/components/library/UpdateChecker.tsx
@@ -46,10 +46,12 @@ function UpdateChecker() {
         const wsc = new WebSocket(`${baseWebsocketUrl}/api/v1/update`);
         wsc.onmessage = (e) => {
             const data = JSON.parse(e.data) as IUpdateStatus;
-            const { COMPLETE, RUNNING, PENDING } = data.statusMap;
+            const { COMPLETE = [], RUNNING = [], PENDING = [] } = data.statusMap;
 
             setLoading(data.running);
-            const currentProgress = 100 * (COMPLETE / (COMPLETE + RUNNING + PENDING));
+            const currentProgress = 100 * (
+                COMPLETE.length / (COMPLETE.length + RUNNING.length + PENDING.length)
+            );
 
             setProgress(Number.isNaN(currentProgress) ? 0 : currentProgress);
         };
diff --git a/src/typings.d.ts b/src/typings.d.ts
index 2fcc9fe0..dd189523 100644
--- a/src/typings.d.ts
+++ b/src/typings.d.ts
@@ -197,9 +197,9 @@ interface IQueue {
 interface IUpdateStatus {
     running: boolean
     statusMap: {
-        COMPLETE: number,
-        RUNNING: number,
-        PENDING: number
+        COMPLETE?: IManga[],
+        RUNNING?: IManga[],
+        PENDING?: IManga[]
     }
 }