diff --git a/public/js/external/md_to_html.js b/public/js/external/md_to_html.js
index c3b7911..68c70e1 100644
--- a/public/js/external/md_to_html.js
+++ b/public/js/external/md_to_html.js
@@ -68,7 +68,7 @@ const MD_TRANSFORMS = {
  * @returns The generated HTML string.
  */
 function md_to_html(markdown, transform_config) {
-	let html = markdown;
+	let html = markdown ?? "";
 	for (const transform_name of MD_TRANSFORM_NAMES) {
 		const enabled =
 			typeof transform_config === "undefined" || transform_config[transform_name] !== false;