Listview Checkbox.IsActivated bind to Parent Checkbox.IsChecked

I try to bind the IsActivated Property of a Checkbox to IsChecked of another Checkbox in a Listview. What is wrong?

    <TreeView ItemsSource="{Binding Rulesets}">
        <TreeView.ItemTemplate>
            <HierarchicalDataTemplate ItemsSource="{Binding Rules}">
                <StackPanel Orientation="Horizontal">
                    <CheckBox Name="rulesetCheckbox" IsChecked="{Binding IsActivated}"></CheckBox>
                    <TextBlock Text="{Binding Name}" />
                </StackPanel>
                <HierarchicalDataTemplate.ItemTemplate>
                    <DataTemplate>
                        <StackPanel Orientation="Horizontal">
                            <CheckBox IsEnabled="{Binding ElementName=rulesetCheckbox, Path=IsChecked}"  IsChecked="{Binding IsActivated}"></CheckBox>
                            <TextBlock Text="{Binding Name}" />
                        </StackPanel>
                    </DataTemplate>
                </HierarchicalDataTemplate.ItemTemplate>
            </HierarchicalDataTemplate>
        </TreeView.ItemTemplate>
    </TreeView>

Thanks!