diff --git a/runtime/syntax/m4.vim b/runtime/syntax/m4.vim
index 8d28ab3a97..5100b4c3ac 100644
--- a/runtime/syntax/m4.vim
+++ b/runtime/syntax/m4.vim
@@ -5,6 +5,7 @@
 " 2025 Sep 2 by Vim project: fix a few syntax issues #18192
 " 2025 Sep 5 by Vim project: introduce m4Disabled region #18200
 " 2025 Sep 6 by Vim project: remove m4Function heuristics #18211
+" 2025 Sep 6 by Vim project: remove m4Type and m4Function #18223
 
 " quit when a syntax file was already loaded
 if !exists("main_syntax")
@@ -57,12 +58,12 @@ syn match  m4Constants "\<\(m4_\)\=__file__"
 syn match  m4Constants "\<\(m4_\)\=__line__"
 syn keyword m4Constants divnum sysval m4_divnum m4_sysval
 syn region m4Paren    matchgroup=m4Delimiter start="(" end=")" contained contains=@m4Top
-syn region m4Command  matchgroup=m4Function  start="\<\(m4_\)\=\(define\|defn\|pushdef\)(" end=")" contains=@m4Top
+syn region m4Command  matchgroup=m4Define  start="\<\(m4_\)\=\(define\|defn\|pushdef\)(" end=")" contains=@m4Top
 syn region m4Command  matchgroup=m4Preproc   start="\<\(m4_\)\=\(include\|sinclude\)("he=e-1 end=")" contains=@m4Top
 syn region m4Command  matchgroup=m4Statement start="\<\(m4_\)\=\(syscmd\|esyscmd\|ifdef\|ifelse\|indir\|builtin\|shift\|errprint\|m4exit\|changecom\|changequote\|changeword\|m4wrap\|debugfile\|divert\|undivert\)("he=e-1 end=")" contains=@m4Top
 syn region m4Command  matchgroup=m4Builtin start="\<\(m4_\)\=\(len\|index\|regexp\|substr\|translit\|patsubst\|format\|incr\|decr\|eval\|maketemp\)("he=e-1 end=")" contains=@m4Top
 syn keyword m4Statement divert undivert
-syn region m4Command  matchgroup=m4Type      start="\<\(m4_\)\=\(undefine\|popdef\)("he=e-1 end=")" contains=@m4Top
+syn region m4Command  matchgroup=m4Define      start="\<\(m4_\)\=\(undefine\|popdef\)("he=e-1 end=")" contains=@m4Top
 syn cluster m4Top     contains=m4Comment,m4Constants,m4Special,m4Variable,m4Paren,m4Command,m4Statement,m4Quoted
 
 " Define the default highlighting.
@@ -71,10 +72,10 @@ hi def link m4QuoteDelim  Delimiter
 hi def link m4Delimiter   Delimiter
 hi def link m4Comment     Comment
 hi def link m4Keyword     Keyword
+hi def link m4Define      Define
 hi def link m4Special     Special
 hi def link m4Statement   Statement
 hi def link m4Preproc     PreProc
-hi def link m4Type        Type
 hi def link m4Variable    Special
 hi def link m4Constants   Constant
 hi def link m4Builtin     Statement