diff --git a/README.md b/README.md
index 59bf9e4..b666b05 100644
--- a/README.md
+++ b/README.md
@@ -22,20 +22,21 @@ and send it to your friends :)
 note, that the api is not yet complete,
 this is just a, maybe already useful, proof-of-concept for now.
 
-
 ## use type-checking and completion
 
 If you are using vscode you can have autocompletion and type-checking even without using typescript.
 
 just add these two lines to your javascript source files:
+
 ```js
 //@ts-check
 /** @typedef {import('./webxdc').WEBxDC} WEBxDC */
 ```
 
 Without vscode you need to install typescript and then run the check manually.
+
 ```sh
 npm -g typescript
-tsc --noEmit --allowJs webxdc.js # to check if types and simulator are in sync
-tsc --noEmit --allowJs your_js_file.js
-``` 
\ No newline at end of file
+tsc --noEmit --allowJs --lib es2015,dom webxdc.js # to check if types and simulator are in sync
+tsc --noEmit --allowJs --lib es2015,dom your_js_file.js
+```