diff --git a/mailcow/src/mailcow-dockerized/data/web/inc/lib/CSSminifierExtended.php b/mailcow/src/mailcow-dockerized/data/web/inc/lib/CSSminifierExtended.php
new file mode 100644
index 0000000..125381c
--- /dev/null
+++ b/mailcow/src/mailcow-dockerized/data/web/inc/lib/CSSminifierExtended.php
@@ -0,0 +1,18 @@
+<?php
+
+use MatthiasMullie\Minify\CSS;
+
+class CSSminifierExtended extends CSS {
+
+    public function getDataHash() {
+        return sha1(json_encode($this->accessProtected($this,'data')));
+    }
+
+    private function accessProtected($obj, $prop) {
+        $reflection = new ReflectionClass($obj);
+        $property = $reflection->getProperty($prop);
+        $property->setAccessible(true);
+        return $property->getValue($obj);
+    }
+
+}
\ No newline at end of file