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 0add9736b..b7b2e3e34 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
@@ -68,7 +68,7 @@ data class Book(
             variableMap = if (isEmpty(variable)) {
                 HashMap()
             } else {
-                GSON.fromJsonObject<HashMap<String, String>>(variable)
+                GSON.fromJsonObject(variable)
             }
         }
     }