diff --git a/index.html b/index.html
index 9a82097..a9ed60e 100644
--- a/index.html
+++ b/index.html
@@ -170,7 +170,7 @@ You can also build from source: <a href="https://github.com/coolwanglu/pdf2htmlE
                 <input type="image" src="https://www.paypal.com/en_US/i/btn/btn_donate_LG.gif" border="0" name="submit" alt="PayPal — The safer, easier way to pay online.">
                 <img alt="" border="0" src="https://www.paypalobjects.com/en_GB/i/scr/pixel.gif" width="1" height="1">
             </form>
-
+            Tip the author <iframe style="border:0;margin:0;padding:0;vertical-align:middle;" src="https://www.gittip.com/coolwanglu/widget.html" width="48pt" height="22pt"></iframe>
           <h3>Thank you</h3>
           <ul>
               <li>Markus Doppelbauer</li>