diff --git a/static/index.html b/static/index.html
index c8df13a..85be89a 100644
--- a/static/index.html
+++ b/static/index.html
@@ -46,7 +46,7 @@
 <body>
 
 <nav role="none" aria-label="boutton activer/desactiver les animations" id="play">
-    <ul aria-label="boutton activer/desactiver les animations" role="toolbar" aria-orientation="vertical" class="toggleButton">
+    <ul aria-label="boutton activer/desactiver les animations" role="toolbar" aria-orientation="undefined" class="toggleButton">
         <li role="none">
         <pre class="toggleable" aria-hidden="true">
   |‾‾‾‾‾‾‾‾‾|
