diff --git a/runtime/syntax/cpp.vim b/runtime/syntax/cpp.vim
index 3ad79d5..5437580 100644
--- a/runtime/syntax/cpp.vim
+++ b/runtime/syntax/cpp.vim
@@ -2,7 +2,7 @@
 " Language:	C++
 " Current Maintainer:	vim-jp (https://github.com/vim-jp/vim-cpp)
 " Previous Maintainer:	Ken Shan <ccshan@post.harvard.edu>
-" Last Change:	2021 May 04
+" Last Change:	2021 Aug 23
 
 " quit when a syntax file was already loaded
 if exists("b:current_syntax")
@@ -60,7 +60,7 @@
   syn match cppFloat		display contained "\<\d\+\.\d*\(e[-+]\=\d\+\)\=\([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
   syn match cppFloat		display contained "\<\.\d\+\(e[-+]\=\d\+\)\=\([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
   syn match cppFloat		display contained "\<\d\+e[-+]\=\d\+\([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
-  syn region cppString		start=+\(L\|u\|u8\|U\|R\|LR\|u8R\|uR\|UR\)\="+ skip=+\\\\\|\\"\|\\$+ excludenl end=+"\(sv\|s\|_\i*\)\=+ end='$' contains=cSpecial,cFormat,@Spell
+  syn region cppString		start=+\(L\|u\|u8\|U\)\="+ skip=+\\\\\|\\"\|\\$+ excludenl end=+"\(sv\|s\|_\i*\)\=+ end='$' contains=cSpecial,cFormat,@Spell
 endif
 
 " C++ 17 extensions
@@ -69,6 +69,20 @@
   syn match cppCast		"\<reinterpret_pointer_cast\s*$"
   syn match cppFloat		display contained "\<0x\x*\.\x\+p[-+]\=\d\+\([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
   syn match cppFloat		display contained "\<0x\x\+\.\=p[-+]\=\d\+\([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+
+  " TODO: push this up to c.vim if/when supported in C23
+  syn match cppCharacter	"u8'[^\\]'"
+  syn match cppCharacter	"u8'[^']*'" contains=cSpecial
+  if exists("c_gnu")
+    syn match cppSpecialError	  "u8'\\[^'\"?\\abefnrtv]'"
+    syn match cppSpecialCharacter "u8'\\['\"?\\abefnrtv]'"
+  else
+    syn match cppSpecialError	  "u8'\\[^'\"?\\abfnrtv]'"
+    syn match cppSpecialCharacter "u8'\\['\"?\\abfnrtv]'"
+  endif
+  syn match cppSpecialCharacter display "u8'\\\o\{1,3}'"
+  syn match cppSpecialCharacter display "u8'\\x\x\+'"
+
 endif
 
 " C++ 20 extensions
@@ -99,6 +113,9 @@
 hi def link cppStorageClass	StorageClass
 hi def link cppStructure		Structure
 hi def link cppBoolean		Boolean
+hi def link cppCharacter		cCharacter
+hi def link cppSpecialCharacter		cSpecialCharacter
+hi def link cppSpecialError		cSpecialError
 hi def link cppConstant		Constant
 hi def link cppRawStringDelimiter	Delimiter
 hi def link cppRawString		String