diff --git a/src/main/kotlin/cn/tursom/core/buffer/ByteBuffer.kt b/src/main/kotlin/cn/tursom/core/buffer/ByteBuffer.kt
index c58ac0f..4e223cc 100644
--- a/src/main/kotlin/cn/tursom/core/buffer/ByteBuffer.kt
+++ b/src/main/kotlin/cn/tursom/core/buffer/ByteBuffer.kt
@@ -99,7 +99,8 @@ interface ByteBuffer : Closeable {
 
   fun toString(size: Int): String {
     val bytes = getBytes(size)
-    readPosition += bytes.size
+    // 将测试的字节返还回来
+    readPosition -= bytes.size
     return String(bytes)
   }