Binding to DependencyProperty with no result <p>I have problem with binding to dependency property of my new control.<br> I decided to write some tests to examine this issue.<br></p> <p><strong>Binding from TextBox.Text to another TextBox.Text</strong></p> <p>XAML code:</p> <pre><code>&lt;TextBox Name="Test" Text="{Binding ElementName=Test2, Path=Text, UpdateSourceTrigger=PropertyChanged}" /&gt; &lt;TextBox Name="Test2" Grid.Row="2" /&gt; </code></pre> <p>The result is good - when I writing something in first TextBox -> second TextBox is updating (conversely too).</p> <p><img src="https://i.stack.imgur.com/i5TzV.png" alt="enter image description here"></p> <p>I created new control -> for example "SuperTextBox" with dependency property "SuperValue".</p> <p>Control XAML code:</p> <pre><code>&lt;UserControl x:Class="WpfApplication2.SuperTextBox" ... Name="Root"&gt; &lt;TextBox Text="{Binding SuperValue, ElementName=Root, UpdateSourceTrigger=PropertyChanged}" /&gt; &lt;/UserControl&gt; </code></pre> <p>Code behind:</p> <pre><code>public partial class SuperTextBox : UserControl { public SuperTextBox() { InitializeComponent(); } public static readonly DependencyProperty SuperValueProperty = DependencyProperty.Register( "SuperValue", typeof(string), typeof(SuperTextBox), new FrameworkPropertyMetadata(string.Empty) ); public string SuperValue { get { return (string)GetValue(SuperValueProperty); } set { SetValue(SuperValueProperty, value); } } } </code></pre> <p>Ok, and now tests!</p> <p><strong>Binding from TextBox.Text to SuperTextBox.SuperValue</strong></p> <pre><code> &lt;TextBox x:Name="Test1" Text="{Binding ElementName=Test2, Path=SuperValue, UpdateSourceTrigger=PropertyChanged}" /&gt; &lt;local:SuperTextBox x:Name="Test2" Grid.Row="2"/&gt; </code></pre> <p>Test is correct too! When I writing something in TextBox, SuperTextBox is updating. When i writing in SuperTextBox, TextBox is updating. All is ok!</p> <p>Now a problem:<br> <strong>Binding from SuperTextBox.SuperValue to TextBox.Text</strong></p> <pre><code> &lt;TextBox x:Name="Test1"/&gt; &lt;local:SuperTextBox x:Name="Test2" SuperValue="{Binding ElementName=Test1, Path=Text, UpdateSourceTrigger=PropertyChanged}" Grid.Row="2"/&gt; </code></pre> <p>In this case, when I writing something in SuperTextBox, TextBox is not updating! <img src="https://i.stack.imgur.com/eqSJP.png" alt="enter image description here"></p> <p>How can I fix this?</p> <p>PS: Question is very very long, I am sorry for that, but i tried exactly describe my problem.</p>