diff --git a/web/viewer.css b/web/viewer.css
index 8f4014139..a9315c983 100644
--- a/web/viewer.css
+++ b/web/viewer.css
@@ -494,6 +494,16 @@ canvas {
   -webkit-box-shadow: 0px 2px 10px #ff0;
 }
 
+.loadingIcon {
+  position: absolute;
+  display: block;
+  left: 0;
+  top: 0;
+  right: 0;
+  bottom: 0;
+  background: url('images/loading-icon.gif') center no-repeat;
+}
+
 #loadingBox {
   margin: 100px 0;
   text-align: center;