diff --git a/src/markdown/index.ts b/src/markdown/index.ts
index 91db7a5..01dc613 100644
--- a/src/markdown/index.ts
+++ b/src/markdown/index.ts
@@ -10,10 +10,8 @@ import markedCodeBlockYamlTag from "./code-block-yaml-tag";
 let globalIconPrefix: string | undefined = undefined;
 function overrideIconPrefix(path?: string) {
   globalIconPrefix = path;
-  return {
-    [Symbol.dispose]() {
-      globalIconPrefix = undefined;
-    },
+  return () => {
+    globalIconPrefix = undefined;
   };
 }
 
@@ -96,8 +94,12 @@ const marked = new Marked()
   );
 
 export function parseMarkdown(content: string, iconPrefix?: string): string {
-  using prefix = overrideIconPrefix(iconPrefix);
-  return marked.parse(content.trimStart()) as string;
+  const restore = overrideIconPrefix(iconPrefix);
+  try {
+    return marked.parse(content.trimStart()) as string;
+  } finally {
+    restore();
+  }
 }
 
 export { marked };
diff --git a/tsconfig.json b/tsconfig.json
index 146fd53..d961dbf 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -15,8 +15,8 @@
     "outDir": "./dist",
     "rootDir": "./src",
     "lib": ["ES2022", "DOM", "DOM.Iterable"],
-    "types": ["node", "jest"]
+    "types": ["node", "jest"],
   },
   "include": ["src/**/*"],
-  "exclude": ["node_modules", "dist"]
+  "exclude": ["node_modules", "dist"],
 }