diff --git a/public/image/GitHub-Mark-Light-32px.png b/public/image/GitHub-Mark-Light-32px.png
new file mode 100644
index 0000000..628da97
Binary files /dev/null and b/public/image/GitHub-Mark-Light-32px.png differ
diff --git a/public/index.html b/public/index.html
index d603423..d81d98e 100644
--- a/public/index.html
+++ b/public/index.html
@@ -51,7 +51,7 @@
     </div>
 
     <div id="footer">
-      <div id="copyright">Copyright 2018 <a href="https://twitter.com/tanabe">Hideaki Tanabe</a>.</div>
+      <div id="copyright"><a href="https://github.com/tanabe/markdown-live-preview"><img src="image/GitHub-Mark-Light-32px.png"></a></div>
     </div>
 
     <script type="text/javascript">