diff --git a/core/modules/system/css/system.theme.css b/core/modules/system/css/system.theme.css
index 9803fdc..dee0a32 100644
--- a/core/modules/system/css/system.theme.css
+++ b/core/modules/system/css/system.theme.css
@@ -318,8 +318,8 @@ th.checkbox {
   padding: 0 1px;
   height: 16px;
   border-radius: 10em;
+  -webkit-animation: animate-stripes 3s linear infinite;
+  -moz-animation: animate-stripes 3s linear infinite;
-  -webkit-animation: animate-stripes 3s linear infinite; /* LTR */
-  -moz-animation: animate-stripes 3s linear infinite; /* LTR */
   -webkit-transition: width 0.5s ease-out;
   transition: width 0.5s ease-out;
 }