1 files changed, 5 insertions, 0 deletions
diff --git a/WebContent/VAADIN/themes/valo/components/_tree.scss b/WebContent/VAADIN/themes/valo/components/_tree.scss
index 4b9fe33c4a..01840139b3 100644
--- a/WebContent/VAADIN/themes/valo/components/_tree.scss
+++ b/WebContent/VAADIN/themes/valo/components/_tree.scss
@@ -45,6 +45,10 @@ $v-tree-expand-animation-enabled: false !default;
       width: 1.9em;
       height: $v-tree-row-height;
       cursor: pointer;
+      // IE 9/10 need some color so that this element can receive mouse events.
+      // 'red' just happens to be the shortest color name.
+      background: red;
+      opacity: 0;
 
       .v-ie8 & {
         content: "+";
@@ -53,6 +57,7 @@ $v-tree-expand-animation-enabled: false !default;
         vertical-align: top;
         @include valo-tree-collapsed-icon-style;
         text-align: center;
+        background: transparent;
       }
     }