diff --git a/public/css/icinga/dev.less b/public/css/icinga/dev.less
new file mode 100644
index 000000000..f4af5426a
--- /dev/null
+++ b/public/css/icinga/dev.less
@@ -0,0 +1,10 @@
+/*! Icinga Web 2 | (c) 2013-2015 Icinga Development Team | GPLv2+ */
+
+#fontsize-calc {
+  display: none;
+  width: 1000em;
+  height: 1em;
+  font-size: 1em;
+  position: absolute;
+  top: -2em;
+}