diff --git a/server/objects/mediaTypes/Book.js b/server/objects/mediaTypes/Book.js
index aaaa523e..bc34bbb8 100644
--- a/server/objects/mediaTypes/Book.js
+++ b/server/objects/mediaTypes/Book.js
@@ -444,7 +444,7 @@ class Book {
               id: c.id + currChapterId,
               start: c.start + currStartTime,
               end: c.end + currStartTime,
-            }))
+            })) ?? []
             this.chapters = this.chapters.concat(chapters)
 
             currChapterId += file.chapters?.length ?? 0