diff --git a/build/lib/stylelint/vscode-known-variables.json b/build/lib/stylelint/vscode-known-variables.json
index ebdbb5f7d77..4d0c82b3149 100644
--- a/build/lib/stylelint/vscode-known-variables.json
+++ b/build/lib/stylelint/vscode-known-variables.json
@@ -382,6 +382,7 @@
 		"--vscode-inlineChat-background",
 		"--vscode-inlineChat-border",
 		"--vscode-inlineChat-foreground",
+		"--vscode-inlineChat-regionHighlight",
 		"--vscode-inlineChat-shadow",
 		"--vscode-inlineChatDiff-inserted",
 		"--vscode-inlineChatDiff-removed",
@@ -994,4 +995,4 @@
 		"--comment-thread-state-color",
 		"--comment-thread-state-background-color"
 	]
-}
\ No newline at end of file
+}