diff --git a/static/bootstrap/stylesheets/bootstrap/mixins/_opacity.scss b/static/bootstrap/stylesheets/bootstrap/mixins/_opacity.scss
new file mode 100644
index 0000000000000000000000000000000000000000..88e9a576abd795a9d0734542ff7e58e44a08d9a3
--- /dev/null
+++ b/static/bootstrap/stylesheets/bootstrap/mixins/_opacity.scss
@@ -0,0 +1,8 @@
+// Opacity
+
+@mixin opacity($opacity) {
+  opacity: $opacity;
+  // IE8 filter
+  $opacity-ie: ($opacity * 100);
+  filter: alpha(opacity=$opacity-ie);
+}