diff --git a/lib/resty/lock.lua b/lib/resty/lock.lua
index 8dab49f..62e9278 100644
--- a/lib/resty/lock.lua
+++ b/lib/resty/lock.lua
@@ -14,7 +14,7 @@ local debug = ngx.config.debug
 local setmetatable = setmetatable
 local tonumber = tonumber

-local _M = { _VERSION = '0.08' }
+local _M = { _VERSION = '0.09' }
 local mt = { __index = _M }

 local ERR = ngx.ERR