diff --git a/app/src/main/java/io/legado/app/data/entities/Book.kt b/app/src/main/java/io/legado/app/data/entities/Book.kt
index e02d8ff06..2274a973c 100644
--- a/app/src/main/java/io/legado/app/data/entities/Book.kt
+++ b/app/src/main/java/io/legado/app/data/entities/Book.kt
@@ -19,7 +19,7 @@ import kotlin.math.max
 data class Book(
     @PrimaryKey
     var bookUrl: String = "",                   // 详情页Url(本地书源存储完整文件路径)
-    var tocUrl: String? = null,                    // 目录页Url (toc=table of Contents)
+    var tocUrl: String = "",                    // 目录页Url (toc=table of Contents)
     var origin: String = BookType.local,        // 书源URL(默认BookType.local)
     var originName: String = "",                //书源名称
     var name: String? = null,                   // 书籍名称(书源获取)
diff --git a/app/src/main/java/io/legado/app/data/entities/SearchBook.kt b/app/src/main/java/io/legado/app/data/entities/SearchBook.kt
index fea706639..819d45758 100644
--- a/app/src/main/java/io/legado/app/data/entities/SearchBook.kt
+++ b/app/src/main/java/io/legado/app/data/entities/SearchBook.kt
@@ -26,7 +26,7 @@ data class SearchBook(
     var intro: String? = null,
     var wordCount: String? = null,
     var latestChapterTitle: String? = null,
-    var tocUrl: String? = null,                    // 目录页Url (toc=table of Contents)
+    var tocUrl: String = "",                    // 目录页Url (toc=table of Contents)
     var time: Long = 0L,
     var variable: String? = null,
     var bookInfoHtml: String? = null,