diff --git a/highlighter.inc.php b/highlighter.inc.php
index 3a797a2..ffe3bf3 100644
--- a/highlighter.inc.php
+++ b/highlighter.inc.php
@@ -55,11 +55,11 @@
         for (let i = 0; i< lst.length; i++) {
             if (lst[i].parentNode.classList.contains("list1")){
                 var text = lst[i].innerHTML;
-                var reg = new RegExp(pat, "g");
-                if (lst[i].children[0].tagName == "span") {
-                    lst[i].children[0].style = style;
+                var elm = lst[i].children;
+                if (elm.length > 0 && elm[0].classList.contains("highlighter")) {
                 } else {
-                    lst[i].innerHTML = text.replace(reg, '<span style="$style">$&</span>');
+                    var reg = new RegExp(pat, "g");
+                    lst[i].innerHTML = text.replace(reg, '<span class="highlighter" style="$style">$&</span>');
                 }
             }
         }