diff --git a/Doc/tools/extensions/peg_highlight.py b/Doc/tools/extensions/peg_highlight.py
index 4bdc2ee1861..5ab5530d269 100644
--- a/Doc/tools/extensions/peg_highlight.py
+++ b/Doc/tools/extensions/peg_highlight.py
@@ -16,6 +16,7 @@ class PEGLexer(RegexLexer):
         - Rule types
         - Rule options
         - Rules named `invalid_*` or `incorrect_*`
+        - Rules with `RAISE_SYNTAX_ERROR`
     """
 
     name = "PEG"
@@ -59,6 +60,7 @@ class PEGLexer(RegexLexer):
             (r"^(\s+\|\s+.*invalid_\w+.*\n)", bygroups(None)),
             (r"^(\s+\|\s+.*incorrect_\w+.*\n)", bygroups(None)),
             (r"^(#.*invalid syntax.*(?:.|\n)*)", bygroups(None),),
+            (r"^(\s+\|\s+.*\{[^}]*RAISE_SYNTAX_ERROR[^}]*\})\n", bygroups(None)),
         ],
         "root": [
             include("invalids"),