diff --git a/app/src/main/java/us/shandian/giga/get/DownloadMission.java b/app/src/main/java/us/shandian/giga/get/DownloadMission.java
index 0c97433fd..01401c0db 100644
--- a/app/src/main/java/us/shandian/giga/get/DownloadMission.java
+++ b/app/src/main/java/us/shandian/giga/get/DownloadMission.java
@@ -70,7 +70,7 @@ public class DownloadMission extends Mission {
     static final int ERROR_HTTP_FORBIDDEN = 403;
 
     private StreamInfo streamInfo;
-    protected volatile Bitmap thumbnail;
+    protected transient volatile Bitmap thumbnail;
     protected volatile boolean thumbnailFetched = false;
 
     /**