diff --git a/less/progress-bars.less b/less/progress-bars.less
index 3d4e6306ff..3ac52a29eb 100644
--- a/less/progress-bars.less
+++ b/less/progress-bars.less
@@ -6,6 +6,13 @@
 // Bar animations
 // -------------------------
 
+// WebKit
+@-webkit-keyframes progress-bar-stripes {
+  from  { background-position: 40px 0; }
+  to    { background-position: 0 0; }
+}
+
+// Spec and IE10+
 @keyframes progress-bar-stripes {
   from  { background-position: 40px 0; }
   to    { background-position: 0 0; }