diff --git a/mainwindow.ui b/mainwindow.ui
--- a/mainwindow.ui
+++ b/mainwindow.ui
@@ -442,6 +442,9 @@
    <property name="checkable">
     <bool>true</bool>
    </property>
+   <property name="checked">
+    <bool>true</bool>
+   </property>
    <property name="text">
     <string>Start</string>
    </property>