diff --git a/dist/css/bootstrap.css b/dist/css/bootstrap.css
index 5fde370352..accc2303e6 100644
--- a/dist/css/bootstrap.css
+++ b/dist/css/bootstrap.css
@@ -3558,6 +3558,7 @@ tbody.collapse.in {
   margin-left: 2px;
   vertical-align: middle;
   border-top: 4px dashed;
+  border-top: 4px solid\9;
   border-right: 4px solid transparent;
   border-left: 4px solid transparent;
 }
diff --git a/less/dropdowns.less b/less/dropdowns.less
index af344607bd..f47a4bce8b 100644
--- a/less/dropdowns.less
+++ b/less/dropdowns.less
@@ -11,6 +11,7 @@
   margin-left: 2px;
   vertical-align: middle;
   border-top:   @caret-width-base dashed;
+  border-top:   @caret-width-base ~"solid\9"; // IE8
   border-right: @caret-width-base solid transparent;
   border-left:  @caret-width-base solid transparent;
 }