I'm loading the .ui file, where one of the widgets (QComboBox) has a dynamic property (http://qt-project.org/doc/qt-5/properties.html#dynamic-properties). The UI file looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
<class>PopulateScriptConfig</class>
<widget class="QWidget" name="PopulateScriptConfig">
  <property name="geometry">
  <rect>
    <x>0</x>
    <y>0</y>
    <width>400</width>
    <height>300</height>
  </rect>
  </property>
  <property name="windowTitle">
  <string>Form</string>
  </property>
  <layout class="QVBoxLayout" name="verticalLayout">
  <item>
    <widget class="QGroupBox" name="langGroup">
    <property name="title">
      <string>Language</string>
    </property>
    <layout class="QVBoxLayout" name="verticalLayout_3">
      <item>
      <widget class="QComboBox" name="langCombo">
        <property name="ScriptingLangCombo" stdset="0">
        <bool>true</bool>
        </property>
      </widget>
      </item>
    </layout>
    </widget>
  </item>
  <item>
    <widget class="QGroupBox" name="codeGroup">
    <property name="title">
      <string>Implementation</string>
    </property>
    <layout class="QVBoxLayout" name="verticalLayout_2">
      <item>
      <widget class="QPlainTextEdit" name="codeEdit"/>
      </item>
    </layout>
    </widget>
  </item>
  </layout>
</widget>
<resources/>
<connections/>
</ui>

The important part is:

      <widget class="QComboBox" name="langCombo">
        <property name="ScriptingLangCombo" stdset="0">
        <bool>true</bool>
        </property>
      </widget>

I'm loading the file with QUiLoader::load(). Note, that I have extended the QUiLoader class, but only to access createWidget() method, where I can query each widget like this:

QWidget* UiLoader::createWidget(const QString& className, QWidget* parent, const QString& name)
{
    QWidget* w = QUiLoader::createWidget(className, parent, name);
    qDebug() << w->dynamicPropertyNames();
    return w;
}

As a result I see empty list displayed, so it seems like the dynamic property is completly ignored.

Any ideas?

P.S. I've made sure that I load correct file. 3 times.