diff --git a/runtime/syntax/generator/vim.vim.base b/runtime/syntax/generator/vim.vim.base
index 25c67ec..0f8ab0a 100644
--- a/runtime/syntax/generator/vim.vim.base
+++ b/runtime/syntax/generator/vim.vim.base
@@ -3,7 +3,7 @@
 " Maintainer:	   Hirohito Higashi <h.east.727 ATMARK gmail.com>
 "	   Doug Kearns <dougkearns@gmail.com>
 " URL:	   https://github.com/vim-jp/syntax-vim-ex
-" Last Change:	   2024 Mar 28
+" Last Change:	   2024 Mar 31
 " Former Maintainer: Charles E. Campbell
 
 " DO NOT CHANGE DIRECTLY.
@@ -249,7 +249,7 @@
 
 syn match	vimFunction	"\<fu\%[nction]\>!\=\s*\%(<[sS][iI][dD]>\|[sg]:\)\=\%(\i\|[#.]\|{.\{-1,}}\)\+"	contains=@vimFuncList skipwhite nextgroup=vimFuncParams
 syn match	vimDef	"\<def\s\+new\%(\i\|{.\{-1,}}\)\+"				contains=@vimDefList            nextgroup=vimDefParams
-syn match	vimDef	"\<def\>!\=\s*\%(<[sS][iI][dD]>\|[sg]:\)\=\%(\i\|[#.]\|{.\{-1,}}\)\+"		contains=@vimDefList            nextgroup=vimDefParams
+syn match	vimDef	"\<def\>!\=\s*\%(<[sS][iI][dD]>\|[sg]:\)\=\%(\i\|[#.]\|{.\{-1,}}\)\+"		contains=@vimDefList,vimMethodName            nextgroup=vimDefParams
 
 syn match	vimFuncComment	contained	+".*+ skipwhite skipnl nextgroup=vimFuncBody,vimEndfunction
 syn match	vimDefComment	contained	"#.*" skipwhite skipnl nextgroup=vimDefBody,vimEnddef
@@ -259,6 +259,7 @@
 syn match	vimFuncSID	contained	"\<[sg]:"
 syn keyword	vimFuncKey	contained	fu[nction]
 syn keyword	vimDefKey	contained	def
+syn keyword	vimMethodName	contained	empty len string
 
 syn region	vimFuncParams	contained	matchgroup=Delimiter start="(" skip=+\n\s*\\\|\n\s*"\\ + end=")" skipwhite skipnl nextgroup=vimFuncBody,vimFuncComment,vimEndfunction,vimFuncMod contains=vimFuncParam,@vimContinue
 syn region	vimDefParams	contained	matchgroup=Delimiter start="("		   end=")" skipwhite skipnl nextgroup=vimDefBody,vimDefComment,vimEnddef,vimReturnType	 contains=vimDefParam,vim9Comment
@@ -579,7 +580,7 @@
 " (following Gautam Iyer's suggestion)
 " ==========================
 syn match	vimFunc              	"\%(\%([sSgGbBwWtTlL]:\|<[sS][iI][dD]>\)\=\%(\w\+\.\)*\I[a-zA-Z0-9_.]*\)\ze\s*("                	contains=vimFuncEcho,vimFuncName,vimUserFunc,vimExecute
-syn match	vimUserFunc	contained        	"\%(\%([sSgGbBwWtTlL]:\|<[sS][iI][dD]>\)\=\%(\w\+\.\)*\I[a-zA-Z0-9_.]*\)\|\<\u[a-zA-Z0-9.]*\>\|\<if\>"	contains=vimNotation
+syn match	vimUserFunc	contained        	"\%(\%([sSgGbBwWtTlL]:\|<[sS][iI][dD]>\)\=\%(\w\+\.\)*\I[a-zA-Z0-9_.]*\)\|\<\u[a-zA-Z0-9.]*\>\|\<if\>"	contains=vimNotation,vimMethodName
 syn keyword	vimFuncEcho	contained      	ec ech echo
 
 " User Command Highlighting: {{{2
@@ -589,7 +590,9 @@
 " ====================
 if !exists("g:vimsyn_noerror") && !exists("g:vimsyn_novimfunctionerror")
  " TODO: The new-prefix exception should only apply to constructor definitions.
- syn match	vimFunctionError	"\s\zs\%(new\)\@![a-z0-9]\i\{-}\ze\s*("		contained contains=vimFuncKey,vimFuncBlank
+ " TODO: The |builtin-object-methods| exception should only apply to method
+ " definitions.
+ syn match	vimFunctionError	"\s\zs\%(empty\|len\|new\|string\)\@![a-z0-9]\i\{-}\ze\s*("		contained contains=vimFuncKey,vimFuncBlank
  syn match	vimFunctionError	"\s\zs\%(<[sS][iI][dD]>\|[sSgGbBwWtTlL]:\)\d\i\{-}\ze\s*("	contained contains=vimFuncKey,vimFuncBlank
  syn match	vimElseIfErr	"\<else\s\+if\>"
  syn match	vimBufnrWarn	/\<bufnr\s*(\s*["']\.['"]\s*)/
@@ -1091,6 +1094,7 @@
  hi def link vimMenuPriority	Number
  hi def link vimMenuStatus	Special
  hi def link vimMenutranslateComment	vimComment
+ hi def link vimMethodName	vimFuncName
  hi def link vimMtchComment	vimComment
  hi def link vimNorm	vimCommand
  hi def link vimNotation	Special
diff --git a/runtime/syntax/testdir/dumps/vim_object_methods_00.dump b/runtime/syntax/testdir/dumps/vim_object_methods_00.dump
new file mode 100644
index 0000000..8089fc1
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim_object_methods_00.dump
@@ -0,0 +1,20 @@
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diff --git a/runtime/syntax/testdir/dumps/vim_object_methods_01.dump b/runtime/syntax/testdir/dumps/vim_object_methods_01.dump
new file mode 100644
index 0000000..05bb98f
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim_object_methods_01.dump
@@ -0,0 +1,20 @@
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diff --git a/runtime/syntax/testdir/dumps/vim_object_methods_02.dump b/runtime/syntax/testdir/dumps/vim_object_methods_02.dump
new file mode 100644
index 0000000..7fd4942
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim_object_methods_02.dump
@@ -0,0 +1,20 @@
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diff --git a/runtime/syntax/testdir/dumps/vim_object_methods_99.dump b/runtime/syntax/testdir/dumps/vim_object_methods_99.dump
new file mode 100644
index 0000000..b69bf91
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim_object_methods_99.dump
@@ -0,0 +1,20 @@
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+|c+0#af5f00255&|o|n|s|t| +0#0000000&|n+0#00e0e07&|2|:+0#0000000&| |n+0#af5f00255&|u|m|b|e|r| +0#0000000&|=+0#af5f00255&| +0#0000000&|p|a|i|r|.|l+0#0000001#ffff4012|e|n|(+0#e000e06#ffffff0|)| +0#0000000&@45
+|c+0#af5f00255&|o|n|s|t| +0#0000000&|s+0#00e0e07&|2|:+0#0000000&| |s|t|r|i|n|g| |=+0#af5f00255&| +0#0000000&|p|a|i|r|.|s+0#0000001#ffff4012|t|r|i|n|g|(+0#e000e06#ffffff0|)| +0#0000000&@42
+|e+0#af5f00255&|c|h|o| +0#0000000&|b+0#00e0e07&|2| +0#0000000&|&+0#af5f00255&@1| +0#0000000&|!+0#af5f00255&|e+0#00e0e07&|m|p|t|y|(+0#e000e06&|p+0#00e0e07&|a|i|r|)+0#e000e06&| +0#0000000&@51
+|e+0#af5f00255&|c|h|o| +0#0000000&|n+0#00e0e07&|2| +0#0000000&|=+0#af5f00255&@1| +0#0000000&|2+0#e000002&| +0#0000000&|&+0#af5f00255&@1| +0#0000000&|l+0#00e0e07&|e|n|(+0#e000e06&|p+0#00e0e07&|a|i|r|)+0#e000e06&| +0#0000000&|=+0#af5f00255&@1| +0#0000000&|2+0#e000002&| +0#0000000&@44
+>e+0#af5f00255&|c|h|o| +0#0000000&|s+0#00e0e07&|2| +0#0000000&|=+0#af5f00255&@1| +0#0000000&|'+0#e000002&|(|0|,| |1|)|'| +0#0000000&|&+0#af5f00255&@1| +0#0000000&|s+0#00e0e07&|t|r|i|n|g|(+0#e000e06&|p+0#00e0e07&|a|i|r|)+0#e000e06&| +0#0000000&|=+0#af5f00255&@1| +0#0000000&|'+0#e000002&|(|0|,| |1|)|'| +0#0000000&@27
+@57|5|6|,|1| @9|B|o|t| 
diff --git a/runtime/syntax/testdir/input/vim_object_methods.vim b/runtime/syntax/testdir/input/vim_object_methods.vim
new file mode 100644
index 0000000..d22c7f2
--- /dev/null
+++ b/runtime/syntax/testdir/input/vim_object_methods.vim
@@ -0,0 +1,56 @@
+vim9script
+# VIM_TEST_SETUP hi link vimMethodName Todo
+
+
+# Vim |builtin-object-methods| and namesake builtin functions.
+class PairClassTest
+	public const a: any
+	public const b: any
+
+	def new(a: any, b: any)
+		this.a = a
+		this.b = b
+	enddef
+
+	def empty(): bool
+		return false
+	enddef
+	def len(): number
+		return 2
+	enddef
+	def string(): string
+		return printf('(%s, %s)', this.a, this.b)
+	enddef
+endclass
+
+enum MarkerEnumTest
+	INSTANCE
+
+	def NoOp()
+	enddef
+
+	def empty(): bool
+		return true
+	enddef
+	def len(): number
+		return 0
+	enddef
+	def string(): string
+		return this.name
+	enddef
+endenum
+
+const b1: bool = empty(MarkerEnumTest.INSTANCE)
+const n1: number = len(MarkerEnumTest.INSTANCE)
+const s1: string = string(MarkerEnumTest.INSTANCE)
+echo b1 && MarkerEnumTest.INSTANCE.empty()
+echo n1 == 0 && MarkerEnumTest.INSTANCE.len() == 0
+echo s1 == 'INSTANCE' && MarkerEnumTest.INSTANCE.string() == 'INSTANCE'
+
+const pair: PairClassTest = PairClassTest.new(0, 1)
+const b2: bool = !pair.empty()
+const n2: number = pair.len()
+const s2: string = pair.string()
+echo b2 && !empty(pair)
+echo n2 == 2 && len(pair) == 2
+echo s2 == '(0, 1)' && string(pair) == '(0, 1)'
diff --git a/runtime/syntax/vim.vim b/runtime/syntax/vim.vim
index c68f0fe..5b95670 100644
--- a/runtime/syntax/vim.vim
+++ b/runtime/syntax/vim.vim
@@ -3,7 +3,7 @@
 " Maintainer:	   Hirohito Higashi <h.east.727 ATMARK gmail.com>
 "	   Doug Kearns <dougkearns@gmail.com>
 " URL:	   https://github.com/vim-jp/syntax-vim-ex
-" Last Change:	   2024 Mar 28
+" Last Change:	   2024 Mar 31
 " Former Maintainer: Charles E. Campbell
 
 " DO NOT CHANGE DIRECTLY.
@@ -286,7 +286,7 @@
 
 syn match	vimFunction	"\<fu\%[nction]\>!\=\s*\%(<[sS][iI][dD]>\|[sg]:\)\=\%(\i\|[#.]\|{.\{-1,}}\)\+"	contains=@vimFuncList skipwhite nextgroup=vimFuncParams
 syn match	vimDef	"\<def\s\+new\%(\i\|{.\{-1,}}\)\+"				contains=@vimDefList            nextgroup=vimDefParams
-syn match	vimDef	"\<def\>!\=\s*\%(<[sS][iI][dD]>\|[sg]:\)\=\%(\i\|[#.]\|{.\{-1,}}\)\+"		contains=@vimDefList            nextgroup=vimDefParams
+syn match	vimDef	"\<def\>!\=\s*\%(<[sS][iI][dD]>\|[sg]:\)\=\%(\i\|[#.]\|{.\{-1,}}\)\+"		contains=@vimDefList,vimMethodName            nextgroup=vimDefParams
 
 syn match	vimFuncComment	contained	+".*+ skipwhite skipnl nextgroup=vimFuncBody,vimEndfunction
 syn match	vimDefComment	contained	"#.*" skipwhite skipnl nextgroup=vimDefBody,vimEnddef
@@ -296,6 +296,7 @@
 syn match	vimFuncSID	contained	"\<[sg]:"
 syn keyword	vimFuncKey	contained	fu[nction]
 syn keyword	vimDefKey	contained	def
+syn keyword	vimMethodName	contained	empty len string
 
 syn region	vimFuncParams	contained	matchgroup=Delimiter start="(" skip=+\n\s*\\\|\n\s*"\\ + end=")" skipwhite skipnl nextgroup=vimFuncBody,vimFuncComment,vimEndfunction,vimFuncMod contains=vimFuncParam,@vimContinue
 syn region	vimDefParams	contained	matchgroup=Delimiter start="("		   end=")" skipwhite skipnl nextgroup=vimDefBody,vimDefComment,vimEnddef,vimReturnType	 contains=vimDefParam,vim9Comment
@@ -623,7 +624,7 @@
 " (following Gautam Iyer's suggestion)
 " ==========================
 syn match	vimFunc              	"\%(\%([sSgGbBwWtTlL]:\|<[sS][iI][dD]>\)\=\%(\w\+\.\)*\I[a-zA-Z0-9_.]*\)\ze\s*("                	contains=vimFuncEcho,vimFuncName,vimUserFunc,vimExecute
-syn match	vimUserFunc	contained        	"\%(\%([sSgGbBwWtTlL]:\|<[sS][iI][dD]>\)\=\%(\w\+\.\)*\I[a-zA-Z0-9_.]*\)\|\<\u[a-zA-Z0-9.]*\>\|\<if\>"	contains=vimNotation
+syn match	vimUserFunc	contained        	"\%(\%([sSgGbBwWtTlL]:\|<[sS][iI][dD]>\)\=\%(\w\+\.\)*\I[a-zA-Z0-9_.]*\)\|\<\u[a-zA-Z0-9.]*\>\|\<if\>"	contains=vimNotation,vimMethodName
 syn keyword	vimFuncEcho	contained      	ec ech echo
 
 " User Command Highlighting: {{{2
@@ -633,7 +634,9 @@
 " ====================
 if !exists("g:vimsyn_noerror") && !exists("g:vimsyn_novimfunctionerror")
  " TODO: The new-prefix exception should only apply to constructor definitions.
- syn match	vimFunctionError	"\s\zs\%(new\)\@![a-z0-9]\i\{-}\ze\s*("		contained contains=vimFuncKey,vimFuncBlank
+ " TODO: The |builtin-object-methods| exception should only apply to method
+ " definitions.
+ syn match	vimFunctionError	"\s\zs\%(empty\|len\|new\|string\)\@![a-z0-9]\i\{-}\ze\s*("		contained contains=vimFuncKey,vimFuncBlank
  syn match	vimFunctionError	"\s\zs\%(<[sS][iI][dD]>\|[sSgGbBwWtTlL]:\)\d\i\{-}\ze\s*("	contained contains=vimFuncKey,vimFuncBlank
  syn match	vimElseIfErr	"\<else\s\+if\>"
  syn match	vimBufnrWarn	/\<bufnr\s*(\s*["']\.['"]\s*)/
@@ -1135,6 +1138,7 @@
  hi def link vimMenuPriority	Number
  hi def link vimMenuStatus	Special
  hi def link vimMenutranslateComment	vimComment
+ hi def link vimMethodName	vimFuncName
  hi def link vimMtchComment	vimComment
  hi def link vimNorm	vimCommand
  hi def link vimNotation	Special