diff --git a/src/com/wentch/redkale/convert/bson/BsonByteBufferWriter.java b/src/com/wentch/redkale/convert/bson/BsonByteBufferWriter.java
index c96fdc818..61d07339e 100644
--- a/src/com/wentch/redkale/convert/bson/BsonByteBufferWriter.java
+++ b/src/com/wentch/redkale/convert/bson/BsonByteBufferWriter.java
@@ -21,6 +21,7 @@ public final class BsonByteBufferWriter extends BsonWriter {
     private int index;
 
     public BsonByteBufferWriter(Supplier<ByteBuffer> supplier) {
+        super((byte[]) null);
         this.supplier = supplier;
     }
 
diff --git a/src/com/wentch/redkale/convert/bson/BsonWriter.java b/src/com/wentch/redkale/convert/bson/BsonWriter.java
index 16b86e3da..781ba5c1a 100644
--- a/src/com/wentch/redkale/convert/bson/BsonWriter.java
+++ b/src/com/wentch/redkale/convert/bson/BsonWriter.java
@@ -49,6 +49,10 @@ public class BsonWriter implements Writer {
         return len;
     }
 
+    protected BsonWriter(byte[] bs) {
+        this.content = bs;
+    }
+
     public BsonWriter() {
         this(defaultSize);
     }