diff --git a/src/runtime/internal/ssr.ts b/src/runtime/internal/ssr.ts
index ecffc82fa4..f9cd27bcbc 100644
--- a/src/runtime/internal/ssr.ts
+++ b/src/runtime/internal/ssr.ts
@@ -84,11 +84,11 @@ export function escape(html: string, is_attr = false) {
   while (pattern.test(html)) {
     const i = pattern.lastIndex - 1;
     const ch = html[i];
-    escaped += html.slice(last, i) + (ch === '&' ? '&' : (ch === '"' ? '"' : '<'));
+    escaped += html.substring(last, i) + (ch === '&' ? '&' : (ch === '"' ? '"' : '<'));
     last = i + 1;
   }
 
-	return escaped + html.slice(last);
+	return escaped + html.substring(last);
 }
 
 export function escape_attribute_value(value) {