diff --git a/less/forms.less b/less/forms.less
index 0a5fa2b8676b..dd45148cf0c0 100644
--- a/less/forms.less
+++ b/less/forms.less
@@ -388,6 +388,9 @@ select:focus:required:invalid {
     border: 1px solid #ccc;
     .border-radius(3px 0 0 3px);
   }
+  [class*="icon-"] {
+    .opacity(50);
+  }
   .active {
     background-color: lighten(@green, 30);
     border-color: @green;