diff --git a/src/AdvancedCalculator/Views/MainView.axaml b/src/AdvancedCalculator/Views/MainView.axaml
index 3d6cdd0..b4f9990 100644
--- a/src/AdvancedCalculator/Views/MainView.axaml
+++ b/src/AdvancedCalculator/Views/MainView.axaml
@@ -155,10 +155,9 @@
                                                 <ListBox ItemsSource="{Binding Functions}" BorderThickness="0" SelectedIndex="-1">
                                                     <ListBox.ItemTemplate>
                                                         <DataTemplate x:DataType="m:FunctionDefinitionItem">
-                                                            <Button x:DataType="vm:MainViewModel"
-                                                                    DataContext="{Binding #Root.DataContext}"
-                                                                    Command="{Binding InsertFunctionCommand}"
-                                                                    CommandParameter="{Binding $parent[ListBoxItem].DataContext}"
+                                                            <Button
+                                                                    Command="{Binding $parent[ListBox].DataContext.InsertFunctionCommand}"
+                                                                    CommandParameter="{Binding}"
                                                                     Background="Transparent" BorderThickness="0" Padding="8" MinHeight="36"
                                                                     AutomationProperties.Name="Insert function">
                                                                 <Grid ColumnDefinitions="*,Auto">