diff --git a/doc/doc-api/src/main/java/cn/axzo/nanopart/doc/api/domain/DirectoryAttributes.java b/doc/doc-api/src/main/java/cn/axzo/nanopart/doc/api/domain/DirectoryAttributes.java
index 6f981d7d..9cd898b4 100644
--- a/doc/doc-api/src/main/java/cn/axzo/nanopart/doc/api/domain/DirectoryAttributes.java
+++ b/doc/doc-api/src/main/java/cn/axzo/nanopart/doc/api/domain/DirectoryAttributes.java
@@ -11,4 +11,9 @@ import lombok.Setter;
 @Getter
 public class DirectoryAttributes {
 
+    /**
+     * mock字段, 暂时避免序列化错误
+     */
+    private boolean placeholder;
+
 }