diff --git a/index.d.ts b/index.d.ts
index 4bff2b6..b95bffa 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1,3 +1,9 @@
 export default class MarkdownToolbarElement extends HTMLElement {
   readonly field: HTMLTextAreaElement | undefined | null;
 }
+
+declare global {
+  interface Window {
+    MarkdownToolbarElement: typeof MarkdownToolbarElement
+  }
+}