diff --git a/it4i_theme/header.html b/it4i_theme/header.html
index 0d73cc915d17dfd6078faf0da9b6ee25bd854fea..0619611de15e91f906dadde5c3e08c4606e59423 100644
--- a/it4i_theme/header.html
+++ b/it4i_theme/header.html
@@ -23,7 +23,7 @@
       </div>
     </div>
       <div class="button button-twitter" role="button" aria-label="Twitter">
-        <a href="all.pdf" title="DOWNLOAD PDF VERSION" target="_blank"><img src="/img/download.png" width="30" height="30"></a>
+        <a href="all.pdf" title="DOWNLOAD PDF VERSION" target="_blank"><img src="/img/download.png" width="27" height="27"></a>
       </div>
       <div class="button button-github" role="button" aria-label="GitHub">
         <a href="https://gitlab.it4i.cz/kru0052/docs.it4i" title="on GitLab" target="_blank" ><img src="/img/git.png" width="30" height="30"></a>