diff --git a/Polyhedron/demo/Polyhedron/MainWindow.ui b/Polyhedron/demo/Polyhedron/MainWindow.ui
index 799cc6052fe..4b483dc3f2d 100644
--- a/Polyhedron/demo/Polyhedron/MainWindow.ui
+++ b/Polyhedron/demo/Polyhedron/MainWindow.ui
@@ -1,4 +1,3 @@
-<?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
  <class>MainWindow</class>
  <widget class="QMainWindow" name="MainWindow">