diff --git a/autoload/vimtex/syntax/p/robust_externalize.vim b/autoload/vimtex/syntax/p/robust_externalize.vim
new file mode 100644
index 0000000000..1723bf13de
--- /dev/null
+++ b/autoload/vimtex/syntax/p/robust_externalize.vim
@@ -0,0 +1,67 @@
+" VimTeX - LaTeX plugin for Vim
+"
+" Maintainer: Karl Yngve Lervåg
+" Email:      karl.yngve@gmail.com
+"
+
+function! vimtex#syntax#p#robust_externalize#load(cfg) abort " {{{1
+  " Match environment boundaries
+  syntax match texRobExtEnvBgn contained '\\begin{\%(RobExt\)\?CacheMeCode\|CacheMe}'
+        \ nextgroup=texRobExtEnvOpt,texRobExtEnvArg skipwhite skipnl
+        \ contains=texCmdEnv
+  call vimtex#syntax#core#new_opt('texRobExtEnvOpt', {'next': 'texRobExtEnvArg'})
+  call vimtex#syntax#core#new_arg('texRobExtEnvArg', {'contains': 'texRobExtEnvArg'})
+
+  " Match generic environments
+  call vimtex#syntax#core#new_env({
+        \ 'name': '\%(RobExt\)\?CacheMeCode\|CacheMe',
+        \ 'region': 'texRobExtZone',
+        \ 'contains': 'texCmdEnv,texRobExtEnvBgn',
+        \})
+  call vimtex#syntax#core#new_env({
+        \ 'name': 'PlaceholderPathFromCode',
+        \ 'region': 'texRobExtZone',
+        \ 'contains': 'texCmdEnv,texRobExtEnvBgn',
+        \})
+  call vimtex#syntax#core#new_env({
+        \ 'name': 'SetPlaceholderCode\*\?',
+        \ 'region': 'texRobExtZone',
+        \ 'contains': 'texCmdEnv,texRobExtEnvBgn',
+        \})
+
+  " Add nested syntax support for supported languages
+  for [l:preset, l:target] in [
+        \ ['c', 'c'],
+        \ ['bash', 'bash'],
+        \ ['python', 'python'],
+        \ ['my python', 'python'],
+        \]
+    let l:cluster = vimtex#syntax#nested#include(l:target)
+
+    let l:name = toupper(l:target[0]) . l:target[1:]
+    let l:grp_env = 'texRobExtZone' . l:name
+    let l:options = 'keepend'
+    let l:contains = 'contains=texCmdEnv,texRobExtEnvBgn'
+
+    if empty(l:cluster)
+      execute 'highlight def link' l:grp_env 'texRobExtZone'
+    else
+      let l:contains .= ',' . l:cluster
+    endif
+
+    " Match normal robext environments
+    execute 'syntax region' l:grp_env
+          \ 'start="\\begin{\z(\%(RobExt\)\?CacheMeCode\|CacheMe\)}\_s*{' . l:preset . '[ ,}]"'
+          \ 'end="\\end{\z1}"'
+          \ l:options
+          \ l:contains
+  endfor
+
+  " Specify default highlight groups
+  highlight def link texRobExtEnvArg     texSymbol
+  highlight def link texRobExtEnvArgOpt  texOpt
+  highlight def link texRobExtEnvOpt     texOpt
+  highlight def link texRobExtZone       texZone
+endfunction
+
+" }}}1
diff --git a/test/test-syntax/test-robust-externalize.tex b/test/test-syntax/test-robust-externalize.tex
new file mode 100644
index 0000000000..ee6925dd13
--- /dev/null
+++ b/test/test-syntax/test-robust-externalize.tex
@@ -0,0 +1,46 @@
+\documentclass{article}
+\usepackage{robust-externalize}
+
+\begin{document}
+
+\begin{CacheMeCode}{c}
+  int main() {
+    return 1;
+  }
+\end{CacheMeCode}
+
+\begin{CacheMeCode}{bash, tikz terminal}
+  echo 'test.dat'
+  exit 0
+\end{CacheMeCode}
+\begin{figure}
+  \begin{CacheMeCode}{python matplotlib, add to preamble={\def\hello#1{Hello #1!}}}
+    def f(p: string):
+      return [x + p for x in ('a', 'b')]
+  \end{CacheMeCode}
+\end{figure}
+
+\begin{RobExtCacheMeCode}{my python matplotlib, 
+    add to preamble={\def\hello#1{Hello #1!}}
+  }
+  def f(p: string):
+    return [x + p for x in ('a', 'b')]
+\end{RobExtCacheMeCode}
+
+\begin{CacheMe}{tikzpicture}[scale=0.6]
+  \draw[gray, thick] (-1,2) -- (2,-4);
+  \draw[gray, thick] (-1,-1) -- (2,2);
+  \filldraw[black] (0,0) circle (2pt) node[anchor=west]{Intersection point};
+\end{CacheMe}
+
+\begin{SetPlaceholderCode*}{__PYTHON_TEMP}
+def f(p: string):
+  return [x + p for x in ('a', 'b')]
+\end{SetPlaceholderCode*}
+
+\begin{PlaceholderPathFromCode}[.py]{__PYTHON_TEMP}
+  def f(p: string):
+    return [x + p for x in ('a', 'b')]
+\end{PlaceholderPathFromCode}
+
+\end{document}
diff --git a/test/test-syntax/test-robust-externalize.vim b/test/test-syntax/test-robust-externalize.vim
new file mode 100644
index 0000000000..4d72fe01f9
--- /dev/null
+++ b/test/test-syntax/test-robust-externalize.vim
@@ -0,0 +1,7 @@
+source common.vim
+
+Edit test-robust-externalize.tex
+
+if empty($INMAKE) | finish | endif
+
+call vimtex#test#finished()