diff --git a/runtime/syntax/lua.vim b/runtime/syntax/lua.vim
index 437a1ff..9c5a490 100644
--- a/runtime/syntax/lua.vim
+++ b/runtime/syntax/lua.vim
@@ -1,11 +1,12 @@
 " Vim syntax file
-" Language:     Lua 4.0, Lua 5.0, Lua 5.1 and Lua 5.2
+" Language:     Lua 4.0, Lua 5.0, Lua 5.1, Lua 5.2 and Lua 5.3
 " Maintainer:   Marcus Aurelius Farias <masserahguard-lua 'at' yahoo com>
 " First Author: Carlos Augusto Teixeira Mendes <cmendes 'at' inf puc-rio br>
-" Last Change:  2022 Mar 31
+" Last Change:  2022 Sep 07
 " Options:      lua_version = 4 or 5
-"               lua_subversion = 0 (4.0, 5.0) or 1 (5.1) or 2 (5.2)
-"               default 5.2
+"               lua_subversion = 0 (for 4.0 or 5.0)
+"                               or 1, 2, 3 (for 5.1, 5.2 or 5.3)
+"               the default is 5.3
 
 " quit when a syntax file was already loaded
 if exists("b:current_syntax")
@@ -16,20 +17,98 @@
 set cpo&vim
 
 if !exists("lua_version")
-  " Default is lua 5.2
+  " Default is lua 5.3
   let lua_version = 5
-  let lua_subversion = 2
+  let lua_subversion = 3
 elseif !exists("lua_subversion")
-  " lua_version exists, but lua_subversion doesn't. So, set it to 0
+  " lua_version exists, but lua_subversion doesn't. In this case set it to 0
   let lua_subversion = 0
 endif
 
 syn case match
 
 " syncing method
-syn sync minlines=100
+syn sync minlines=1000
 
-" Comments
+if lua_version >= 5
+  syn keyword luaMetaMethod __add __sub __mul __div __pow __unm __concat
+  syn keyword luaMetaMethod __eq __lt __le
+  syn keyword luaMetaMethod __index __newindex __call
+  syn keyword luaMetaMethod __metatable __mode __gc __tostring
+endif
+
+if lua_version > 5 || (lua_version == 5 && lua_subversion >= 1)
+  syn keyword luaMetaMethod __mod __len
+endif
+
+if lua_version > 5 || (lua_version == 5 && lua_subversion >= 2)
+  syn keyword luaMetaMethod __pairs
+endif
+
+if lua_version > 5 || (lua_version == 5 && lua_subversion >= 3)
+  syn keyword luaMetaMethod __idiv __name
+  syn keyword luaMetaMethod __band __bor __bxor __bnot __shl __shr
+endif
+
+if lua_version > 5 || (lua_version == 5 && lua_subversion >= 4)
+  syn keyword luaMetaMethod __close
+endif
+
+" catch errors caused by wrong parenthesis and wrong curly brackets or
+" keywords placed outside their respective blocks
+
+syn region luaParen transparent start='(' end=')' contains=TOP,luaParenError
+syn match  luaParenError ")"
+syn match  luaError "}"
+syn match  luaError "\<\%(end\|else\|elseif\|then\|until\|in\)\>"
+
+" Function declaration
+syn region luaFunctionBlock transparent matchgroup=luaFunction start="\<function\>" end="\<end\>" contains=TOP
+
+" else
+syn keyword luaCondElse matchgroup=luaCond contained containedin=luaCondEnd else
+
+" then ... end
+syn region luaCondEnd contained transparent matchgroup=luaCond start="\<then\>" end="\<end\>" contains=TOP
+
+" elseif ... then
+syn region luaCondElseif contained containedin=luaCondEnd transparent matchgroup=luaCond start="\<elseif\>" end="\<then\>" contains=TOP
+
+" if ... then
+syn region luaCondStart transparent matchgroup=luaCond start="\<if\>" end="\<then\>"me=e-4 contains=TOP nextgroup=luaCondEnd skipwhite skipempty
+
+" do ... end
+syn region luaBlock transparent matchgroup=luaStatement start="\<do\>" end="\<end\>" contains=TOP
+" repeat ... until
+syn region luaRepeatBlock transparent matchgroup=luaRepeat start="\<repeat\>" end="\<until\>" contains=TOP
+
+" while ... do
+syn region luaWhile transparent matchgroup=luaRepeat start="\<while\>" end="\<do\>"me=e-2 contains=TOP nextgroup=luaBlock skipwhite skipempty
+
+" for ... do and for ... in ... do
+syn region luaFor transparent matchgroup=luaRepeat start="\<for\>" end="\<do\>"me=e-2 contains=TOP nextgroup=luaBlock skipwhite skipempty
+
+syn keyword luaFor contained containedin=luaFor in
+
+" other keywords
+syn keyword luaStatement return local break
+if lua_version > 5 || (lua_version == 5 && lua_subversion >= 2)
+  syn keyword luaStatement goto
+  syn match luaLabel "::\I\i*::"
+endif
+
+" operators
+syn keyword luaOperator and or not
+
+if (lua_version == 5 && lua_subversion >= 3) || lua_version > 5
+  syn match luaSymbolOperator "[#<>=~^&|*/%+-]\|\.\{2,3}"
+elseif lua_version == 5 && (lua_subversion == 1 || lua_subversion == 2)
+  syn match luaSymbolOperator "[#<>=~^*/%+-]\|\.\{2,3}"
+else
+  syn match luaSymbolOperator "[<>=~^*/+-]\|\.\{2,3}"
+endif
+
+" comments
 syn keyword luaTodo            contained TODO FIXME XXX
 syn match   luaComment         "--.*$" contains=luaTodo,@Spell
 if lua_version == 5 && lua_subversion == 0
@@ -40,71 +119,25 @@
   syn region luaComment        matchgroup=luaCommentDelimiter start="--\[\z(=*\)\[" end="\]\z1\]" contains=luaTodo,@Spell
 endif
 
-" First line may start with #!
+" first line may start with #!
 syn match luaComment "\%^#!.*"
 
-" catch errors caused by wrong parenthesis and wrong curly brackets or
-" keywords placed outside their respective blocks
-syn region luaParen      transparent                     start='(' end=')' contains=ALLBUT,luaParenError,luaTodo,luaSpecial,luaIfThen,luaElseifThen,luaElse,luaThenEnd,luaBlock,luaLoopBlock,luaIn,luaStatement
-syn region luaTableBlock transparent matchgroup=luaTable start="{" end="}" contains=ALLBUT,luaBraceError,luaTodo,luaSpecial,luaIfThen,luaElseifThen,luaElse,luaThenEnd,luaBlock,luaLoopBlock,luaIn,luaStatement
-
-syn match  luaParenError ")"
-syn match  luaBraceError "}"
-syn match  luaError "\<\%(end\|else\|elseif\|then\|until\|in\)\>"
-
-" function ... end
-syn region luaFunctionBlock transparent matchgroup=luaFunction start="\<function\>" end="\<end\>" contains=ALLBUT,luaTodo,luaSpecial,luaElseifThen,luaElse,luaThenEnd,luaIn
-
-" if ... then
-syn region luaIfThen transparent matchgroup=luaCond start="\<if\>" end="\<then\>"me=e-4           contains=ALLBUT,luaTodo,luaSpecial,luaElseifThen,luaElse,luaIn nextgroup=luaThenEnd skipwhite skipempty
-
-" then ... end
-syn region luaThenEnd contained transparent matchgroup=luaCond start="\<then\>" end="\<end\>" contains=ALLBUT,luaTodo,luaSpecial,luaThenEnd,luaIn
-
-" elseif ... then
-syn region luaElseifThen contained transparent matchgroup=luaCond start="\<elseif\>" end="\<then\>" contains=ALLBUT,luaTodo,luaSpecial,luaElseifThen,luaElse,luaThenEnd,luaIn
-
-" else
-syn keyword luaElse contained else
-
-" do ... end
-syn region luaBlock transparent matchgroup=luaStatement start="\<do\>" end="\<end\>"          contains=ALLBUT,luaTodo,luaSpecial,luaElseifThen,luaElse,luaThenEnd,luaIn
-
-" repeat ... until
-syn region luaLoopBlock transparent matchgroup=luaRepeat start="\<repeat\>" end="\<until\>"   contains=ALLBUT,luaTodo,luaSpecial,luaElseifThen,luaElse,luaThenEnd,luaIn
-
-" while ... do
-syn region luaLoopBlock transparent matchgroup=luaRepeat start="\<while\>" end="\<do\>"me=e-2 contains=ALLBUT,luaTodo,luaSpecial,luaIfThen,luaElseifThen,luaElse,luaThenEnd,luaIn nextgroup=luaBlock skipwhite skipempty
-
-" for ... do and for ... in ... do
-syn region luaLoopBlock transparent matchgroup=luaRepeat start="\<for\>" end="\<do\>"me=e-2   contains=ALLBUT,luaTodo,luaSpecial,luaIfThen,luaElseifThen,luaElse,luaThenEnd nextgroup=luaBlock skipwhite skipempty
-
-syn keyword luaIn contained in
-
-" other keywords
-syn keyword luaStatement return local break
-if lua_version > 5 || (lua_version == 5 && lua_subversion >= 2)
-  syn keyword luaStatement goto
-  syn match luaLabel "::\I\i*::"
-endif
-syn keyword luaOperator and or not
 syn keyword luaConstant nil
 if lua_version > 4
   syn keyword luaConstant true false
 endif
 
-" Strings
-if lua_version < 5
-  syn match  luaSpecial contained "\\[\\abfnrtv\'\"]\|\\[[:digit:]]\{,3}"
-elseif lua_version == 5
+" strings
+syn match  luaSpecial contained #\\[\\abfnrtv'"[\]]\|\\[[:digit:]]\{,3}#
+if lua_version == 5
   if lua_subversion == 0
-    syn match  luaSpecial contained #\\[\\abfnrtv'"[\]]\|\\[[:digit:]]\{,3}#
     syn region luaString2 matchgroup=luaStringDelimiter start=+\[\[+ end=+\]\]+ contains=luaString2,@Spell
   else
-    if lua_subversion == 1
-      syn match  luaSpecial contained #\\[\\abfnrtv'"]\|\\[[:digit:]]\{,3}#
-    else " Lua 5.2
-      syn match  luaSpecial contained #\\[\\abfnrtvz'"]\|\\x[[:xdigit:]]\{2}\|\\[[:digit:]]\{,3}#
+    if lua_subversion >= 2
+      syn match  luaSpecial contained #\\z\|\\x[[:xdigit:]]\{2}#
+    endif
+    if lua_subversion >= 3
+      syn match  luaSpecial contained #\\u{[[:xdigit:]]\+}#
     endif
     syn region luaString2 matchgroup=luaStringDelimiter start="\[\z(=*\)\[" end="\]\z1\]" contains=@Spell
   endif
@@ -115,7 +148,7 @@
 " integer number
 syn match luaNumber "\<\d\+\>"
 " floating point number, with dot, optional exponent
-syn match luaNumber  "\<\d\+\.\d*\%([eE][-+]\=\d\+\)\=\>"
+syn match luaNumber  "\<\d\+\.\d*\%([eE][-+]\=\d\+\)\="
 " floating point number, starting with a dot, optional exponent
 syn match luaNumber  "\.\d\+\%([eE][-+]\=\d\+\)\=\>"
 " floating point number, without dot, with exponent
@@ -130,8 +163,15 @@
   endif
 endif
 
+" tables
+syn region luaTableBlock transparent matchgroup=luaTable start="{" end="}" contains=TOP,luaStatement
+
+" methods
+syntax match luaFunc ":\@<=\k\+"
+
+" built-in functions
 syn keyword luaFunc assert collectgarbage dofile error next
-syn keyword luaFunc print rawget rawset tonumber tostring type _VERSION
+syn keyword luaFunc print rawget rawset self tonumber tostring type _VERSION
 
 if lua_version == 4
   syn keyword luaFunc _ALERT _ERRORMESSAGE gcinfo
@@ -168,30 +208,26 @@
     syn match   luaFunc /\<package\.loaded\>/
     syn match   luaFunc /\<package\.loadlib\>/
     syn match   luaFunc /\<package\.path\>/
+    syn match   luaFunc /\<package\.preload\>/
     if lua_subversion == 1
       syn keyword luaFunc getfenv setfenv
       syn keyword luaFunc loadstring module unpack
       syn match   luaFunc /\<package\.loaders\>/
-      syn match   luaFunc /\<package\.preload\>/
       syn match   luaFunc /\<package\.seeall\>/
-    elseif lua_subversion == 2
+    elseif lua_subversion >= 2
       syn keyword luaFunc _ENV rawlen
       syn match   luaFunc /\<package\.config\>/
       syn match   luaFunc /\<package\.preload\>/
       syn match   luaFunc /\<package\.searchers\>/
       syn match   luaFunc /\<package\.searchpath\>/
-      syn match   luaFunc /\<bit32\.arshift\>/
-      syn match   luaFunc /\<bit32\.band\>/
-      syn match   luaFunc /\<bit32\.bnot\>/
-      syn match   luaFunc /\<bit32\.bor\>/
-      syn match   luaFunc /\<bit32\.btest\>/
-      syn match   luaFunc /\<bit32\.bxor\>/
-      syn match   luaFunc /\<bit32\.extract\>/
-      syn match   luaFunc /\<bit32\.lrotate\>/
-      syn match   luaFunc /\<bit32\.lshift\>/
-      syn match   luaFunc /\<bit32\.replace\>/
-      syn match   luaFunc /\<bit32\.rrotate\>/
-      syn match   luaFunc /\<bit32\.rshift\>/
+    endif
+
+    if lua_subversion >= 3
+      syn match luaFunc /\<coroutine\.isyieldable\>/
+    endif
+    if lua_subversion >= 4
+      syn keyword luaFunc warn
+      syn match luaFunc /\<coroutine\.close\>/
     endif
     syn match luaFunc /\<coroutine\.running\>/
   endif
@@ -200,6 +236,7 @@
   syn match   luaFunc /\<coroutine\.status\>/
   syn match   luaFunc /\<coroutine\.wrap\>/
   syn match   luaFunc /\<coroutine\.yield\>/
+
   syn match   luaFunc /\<string\.byte\>/
   syn match   luaFunc /\<string\.char\>/
   syn match   luaFunc /\<string\.dump\>/
@@ -218,6 +255,18 @@
     syn match luaFunc /\<string\.match\>/
     syn match luaFunc /\<string\.reverse\>/
   endif
+  if lua_subversion >= 3
+    syn match luaFunc /\<string\.pack\>/
+    syn match luaFunc /\<string\.packsize\>/
+    syn match luaFunc /\<string\.unpack\>/
+    syn match luaFunc /\<utf8\.char\>/
+    syn match luaFunc /\<utf8\.charpattern\>/
+    syn match luaFunc /\<utf8\.codes\>/
+    syn match luaFunc /\<utf8\.codepoint\>/
+    syn match luaFunc /\<utf8\.len\>/
+    syn match luaFunc /\<utf8\.offset\>/
+  endif
+
   if lua_subversion == 0
     syn match luaFunc /\<table\.getn\>/
     syn match luaFunc /\<table\.setn\>/
@@ -225,19 +274,40 @@
     syn match luaFunc /\<table\.foreachi\>/
   elseif lua_subversion == 1
     syn match luaFunc /\<table\.maxn\>/
-  elseif lua_subversion == 2
+  elseif lua_subversion >= 2
     syn match luaFunc /\<table\.pack\>/
     syn match luaFunc /\<table\.unpack\>/
+    if lua_subversion >= 3
+      syn match luaFunc /\<table\.move\>/
+    endif
   endif
   syn match   luaFunc /\<table\.concat\>/
-  syn match   luaFunc /\<table\.sort\>/
   syn match   luaFunc /\<table\.insert\>/
+  syn match   luaFunc /\<table\.sort\>/
   syn match   luaFunc /\<table\.remove\>/
+
+  if lua_subversion == 2
+    syn match   luaFunc /\<bit32\.arshift\>/
+    syn match   luaFunc /\<bit32\.band\>/
+    syn match   luaFunc /\<bit32\.bnot\>/
+    syn match   luaFunc /\<bit32\.bor\>/
+    syn match   luaFunc /\<bit32\.btest\>/
+    syn match   luaFunc /\<bit32\.bxor\>/
+    syn match   luaFunc /\<bit32\.extract\>/
+    syn match   luaFunc /\<bit32\.lrotate\>/
+    syn match   luaFunc /\<bit32\.lshift\>/
+    syn match   luaFunc /\<bit32\.replace\>/
+    syn match   luaFunc /\<bit32\.rrotate\>/
+    syn match   luaFunc /\<bit32\.rshift\>/
+  endif
+
   syn match   luaFunc /\<math\.abs\>/
   syn match   luaFunc /\<math\.acos\>/
   syn match   luaFunc /\<math\.asin\>/
   syn match   luaFunc /\<math\.atan\>/
-  syn match   luaFunc /\<math\.atan2\>/
+  if lua_subversion < 3
+    syn match   luaFunc /\<math\.atan2\>/
+  endif
   syn match   luaFunc /\<math\.ceil\>/
   syn match   luaFunc /\<math\.sin\>/
   syn match   luaFunc /\<math\.cos\>/
@@ -251,25 +321,36 @@
   if lua_subversion == 0
     syn match luaFunc /\<math\.mod\>/
     syn match luaFunc /\<math\.log10\>/
-  else
-    if lua_subversion == 1
-      syn match luaFunc /\<math\.log10\>/
-    endif
+  elseif lua_subversion == 1
+    syn match luaFunc /\<math\.log10\>/
+  endif
+  if lua_subversion >= 1
     syn match luaFunc /\<math\.huge\>/
     syn match luaFunc /\<math\.fmod\>/
     syn match luaFunc /\<math\.modf\>/
-    syn match luaFunc /\<math\.cosh\>/
-    syn match luaFunc /\<math\.sinh\>/
-    syn match luaFunc /\<math\.tanh\>/
+    if lua_subversion == 1 || lua_subversion == 2
+      syn match luaFunc /\<math\.cosh\>/
+      syn match luaFunc /\<math\.sinh\>/
+      syn match luaFunc /\<math\.tanh\>/
+    endif
   endif
-  syn match   luaFunc /\<math\.pow\>/
   syn match   luaFunc /\<math\.rad\>/
   syn match   luaFunc /\<math\.sqrt\>/
-  syn match   luaFunc /\<math\.frexp\>/
-  syn match   luaFunc /\<math\.ldexp\>/
+  if lua_subversion < 3
+    syn match   luaFunc /\<math\.pow\>/
+    syn match   luaFunc /\<math\.frexp\>/
+    syn match   luaFunc /\<math\.ldexp\>/
+  else
+    syn match   luaFunc /\<math\.maxinteger\>/
+    syn match   luaFunc /\<math\.mininteger\>/
+    syn match   luaFunc /\<math\.tointeger\>/
+    syn match   luaFunc /\<math\.type\>/
+    syn match   luaFunc /\<math\.ult\>/
+  endif
   syn match   luaFunc /\<math\.random\>/
   syn match   luaFunc /\<math\.randomseed\>/
   syn match   luaFunc /\<math\.pi\>/
+
   syn match   luaFunc /\<io\.close\>/
   syn match   luaFunc /\<io\.flush\>/
   syn match   luaFunc /\<io\.input\>/
@@ -284,6 +365,7 @@
   syn match   luaFunc /\<io\.tmpfile\>/
   syn match   luaFunc /\<io\.type\>/
   syn match   luaFunc /\<io\.write\>/
+
   syn match   luaFunc /\<os\.clock\>/
   syn match   luaFunc /\<os\.date\>/
   syn match   luaFunc /\<os\.difftime\>/
@@ -295,6 +377,7 @@
   syn match   luaFunc /\<os\.setlocale\>/
   syn match   luaFunc /\<os\.time\>/
   syn match   luaFunc /\<os\.tmpname\>/
+
   syn match   luaFunc /\<debug\.debug\>/
   syn match   luaFunc /\<debug\.gethook\>/
   syn match   luaFunc /\<debug\.getinfo\>/
@@ -307,26 +390,20 @@
   if lua_subversion == 1
     syn match luaFunc /\<debug\.getfenv\>/
     syn match luaFunc /\<debug\.setfenv\>/
-    syn match luaFunc /\<debug\.getmetatable\>/
-    syn match luaFunc /\<debug\.setmetatable\>/
-    syn match luaFunc /\<debug\.getregistry\>/
-  elseif lua_subversion == 2
-    syn match luaFunc /\<debug\.getmetatable\>/
-    syn match luaFunc /\<debug\.setmetatable\>/
-    syn match luaFunc /\<debug\.getregistry\>/
-    syn match luaFunc /\<debug\.getuservalue\>/
-    syn match luaFunc /\<debug\.setuservalue\>/
-    syn match luaFunc /\<debug\.upvalueid\>/
-    syn match luaFunc /\<debug\.upvaluejoin\>/
   endif
-  if lua_subversion >= 3
-    "https://www.lua.org/manual/5.3/manual.html#6.5
-    syn match luaFunc /\<utf8\.char\>/
-    syn match luaFunc /\<utf8\.charpattern\>/
-    syn match luaFunc /\<utf8\.codes\>/
-    syn match luaFunc /\<utf8\.codepoint\>/
-    syn match luaFunc /\<utf8\.len\>/
-    syn match luaFunc /\<utf8\.offset\>/
+  if lua_subversion >= 1
+    syn match luaFunc /\<debug\.getmetatable\>/
+    syn match luaFunc /\<debug\.setmetatable\>/
+    syn match luaFunc /\<debug\.getregistry\>/
+    if lua_subversion >= 2
+      syn match luaFunc /\<debug\.getuservalue\>/
+      syn match luaFunc /\<debug\.setuservalue\>/
+      syn match luaFunc /\<debug\.upvalueid\>/
+      syn match luaFunc /\<debug\.upvaluejoin\>/
+    endif
+    if lua_subversion >= 4
+      syn match luaFunc /\<debug.setcstacklimit\>/
+    endif
   endif
 endif
 
@@ -341,18 +418,18 @@
 hi def link luaStringDelimiter  luaString
 hi def link luaNumber           Number
 hi def link luaOperator         Operator
-hi def link luaIn               Operator
+hi def link luaSymbolOperator   luaOperator
 hi def link luaConstant         Constant
 hi def link luaCond             Conditional
-hi def link luaElse             Conditional
+hi def link luaCondElse         Conditional
 hi def link luaFunction         Function
+hi def link luaMetaMethod       Function
 hi def link luaComment          Comment
 hi def link luaCommentDelimiter luaComment
 hi def link luaTodo             Todo
 hi def link luaTable            Structure
 hi def link luaError            Error
 hi def link luaParenError       Error
-hi def link luaBraceError       Error
 hi def link luaSpecial          SpecialChar
 hi def link luaFunc             Identifier
 hi def link luaLabel            Label