diff --git a/meta/template/debug.lua b/meta/template/debug.lua
index 7db63e497..f62aca6e1 100644
--- a/meta/template/debug.lua
+++ b/meta/template/debug.lua
@@ -146,7 +146,9 @@ function debug.setfenv(object, env) end
 ---|+'"l"' # ---#DESTAIL 'hookmask.l'
 
 ---#DES 'debug.sethook'
----@overload fun(hook: function, mask: hookmask, count?: integer)
+---@overload fun(hook: async fun(), mask: hookmask, count?: integer)
+---@overload fun(thread: thread)
+---@overload fun()
 ---@param thread thread
 ---@param hook   async fun()
 ---@param mask   hookmask
diff --git a/meta/template/os.lua b/meta/template/os.lua
index af9b32781..711a17b67 100644
--- a/meta/template/os.lua
+++ b/meta/template/os.lua
@@ -45,11 +45,11 @@ function os.difftime(t2, t1) end
 
 ---#DES 'os.execute'
 ---#if VERSION <= 5.1 then
----@param command  string
+---@param command? string
 ---@return integer code
 function os.execute(command) end
 ---#else
----@param command string
+---@param command? string
 ---@return boolean?  suc
 ---@return exitcode? exitcode
 ---@return integer?  code