diff --git a/src/core/highlight-vars.js b/src/core/highlight-vars.js
index a93fa69c16..b9ae3bc6f2 100644
--- a/src/core/highlight-vars.js
+++ b/src/core/highlight-vars.js
@@ -30,9 +30,11 @@ export async function run(conf) {
   // remove highlights, cleanup empty class/style attributes
   sub("beforesave", (/** @type {Document} */ outputDoc) => {
     outputDoc.querySelectorAll("var.respec-hl").forEach(el => {
-      el.classList.remove("respec-hl");
-      const classNames = el.classList.toString().replaceAll(/respec-hl-c*/, "");
-      el.classList.value = classNames.trim();
+      for (const cls of el.classList.values()) {
+        if (cls.startsWith("respec-hl")) {
+          el.classList.remove(cls);
+        }
+      }
       if (!el.classList.length) el.removeAttribute("class");
     });
   });