diff --git a/README.md b/README.md
index 55c0ed17..b1258835 100644
--- a/README.md
+++ b/README.md
@@ -274,5 +274,6 @@ braudrate:9600
     print(t.read(nil,t.C))
     -- Don't forget to release it after use
     t = nil
+	ds18b20 = nil
     package.loaded["ds18b20"]=nil   
 ```
diff --git a/lua_modules/ds18b20/ds18b20.CN.md b/lua_modules/ds18b20/ds18b20.CN.md
index a7fba72d..c6092714 100644
--- a/lua_modules/ds18b20/ds18b20.CN.md
+++ b/lua_modules/ds18b20/ds18b20.CN.md
@@ -109,6 +109,7 @@ print(t.readNumber(nil,t.F))
 t1, t2 = t.readNumber()
 -- Don't forget to release it after use
 t = nil
+ds18b20 = nil
 package.loaded["ds18b20"]=nil
 
 ```
@@ -151,6 +152,7 @@ print(t.read())
 print(t.read(nil,t.C))
 -- Don't forget to release it after use
 t = nil
+ds18b20 = nil
 package.loaded["ds18b20"]=nil
 ```
 ####参见
diff --git a/lua_modules/ds18b20/ds18b20.EN.md b/lua_modules/ds18b20/ds18b20.EN.md
index c887dab3..bdf69397 100644
--- a/lua_modules/ds18b20/ds18b20.EN.md
+++ b/lua_modules/ds18b20/ds18b20.EN.md
@@ -107,6 +107,7 @@ print(t.readNumber(nil,t.F))
 t1, t2 = t.readNumber()
 -- Don't forget to release it after use
 t = nil
+ds18b20 = nil
 package.loaded["ds18b20"]=nil
 ```
 ####See also
@@ -148,6 +149,7 @@ print(t.read())
 print(t.read(nil,t.C))
 -- Don't forget to release it after use
 t = nil
+ds18b20 = nil
 package.loaded["ds18b20"]=nil
 ```
 ####See also