diff --git a/src/Avalonia.Themes.Fluent/Controls/CalendarDatePicker.xaml b/src/Avalonia.Themes.Fluent/Controls/CalendarDatePicker.xaml
index 4739a5b9c5..ce580764d7 100644
--- a/src/Avalonia.Themes.Fluent/Controls/CalendarDatePicker.xaml
+++ b/src/Avalonia.Themes.Fluent/Controls/CalendarDatePicker.xaml
@@ -128,7 +128,7 @@
                 <Calendar Name="PART_Calendar"
                           FirstDayOfWeek="{TemplateBinding FirstDayOfWeek}"
                           IsTodayHighlighted="{TemplateBinding IsTodayHighlighted}"
-                          SelectedDate="{TemplateBinding SelectedDate, Mode=TwoWay}"
+                          SelectedDate="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=SelectedDate, Mode=TwoWay}"
                           DisplayDate="{TemplateBinding DisplayDate}"
                           DisplayDateStart="{TemplateBinding DisplayDateStart}"
                           DisplayDateEnd="{TemplateBinding DisplayDateEnd}" />
diff --git a/src/Avalonia.Themes.Simple/Controls/CalendarDatePicker.xaml b/src/Avalonia.Themes.Simple/Controls/CalendarDatePicker.xaml
index 60759eebb1..e09c2f78d0 100644
--- a/src/Avalonia.Themes.Simple/Controls/CalendarDatePicker.xaml
+++ b/src/Avalonia.Themes.Simple/Controls/CalendarDatePicker.xaml
@@ -125,7 +125,7 @@
                       DisplayDateStart="{TemplateBinding DisplayDateStart}"
                       FirstDayOfWeek="{TemplateBinding FirstDayOfWeek}"
                       IsTodayHighlighted="{TemplateBinding IsTodayHighlighted}"
-                      SelectedDate="{TemplateBinding SelectedDate,
+                      SelectedDate="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=SelectedDate,
                                                      Mode=TwoWay}" />
           </Popup>
         </Grid>