diff --git a/core/modules/system/css/system.module.css b/core/modules/system/css/system.module.css
index 6f33ee8..6817a43 100644
--- a/core/modules/system/css/system.module.css
+++ b/core/modules/system/css/system.module.css
@@ -316,7 +316,6 @@ tr .ajax-progress-throbber .throbber {
   clip: rect(1px, 1px, 1px, 1px);
   overflow: hidden;
   height: 1px;
-  width: 1px;
 }
 
 /**