diff --git a/ch06_listing_source.py b/ch06_listing_source.py
index 737244d..7aaa14d 100644
--- a/ch06_listing_source.py
+++ b/ch06_listing_source.py
@@ -228,8 +228,11 @@ def release_lock(conn, lockname, identifier):
     while True:
         try:
             # 检查并确认进程还持有着锁。
-            pipe.watch(lockname)                  
-            if pipe.get(lockname) == identifier:  
+            pipe.watch(lockname)
+            #这里的value是byte类型，所以要转换成string类型，才能进入释放锁的环节
+            value = pipe.get(lockname)
+            value = str(value, encoding = "utf-8")
+            if value == identifier:  
                 # 释放锁。
                 pipe.multi()                  
                 pipe.delete(lockname)