diff --git a/src/Avalonia.Themes.Fluent/Slider.xaml b/src/Avalonia.Themes.Fluent/Slider.xaml
index a57ea6cedd..539c448e0f 100644
--- a/src/Avalonia.Themes.Fluent/Slider.xaml
+++ b/src/Avalonia.Themes.Fluent/Slider.xaml
@@ -64,7 +64,7 @@
                 <TickBar Name="BottomTickBar" Placement="Bottom" Height="{DynamicResource SliderOutsideTickBarThemeHeight}" VerticalAlignment="Top" Margin="0,4,0,0" Grid.Row="2" Grid.ColumnSpan="3" />
                 <Track Name="PART_Track" Grid.Row="1" Grid.ColumnSpan="3" Orientation="Horizontal">
                   <Track.DecreaseButton>
-                    <RepeatButton Name="PART_DecreaseButton" Background="{TemplateBinding Foreground}">
+                    <RepeatButton Name="PART_DecreaseButton" Background="{TemplateBinding Foreground}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
                       <RepeatButton.Template>
                         <ControlTemplate>
                           <Grid>
@@ -76,7 +76,7 @@
                     </RepeatButton>
                   </Track.DecreaseButton>
                   <Track.IncreaseButton>
-                    <RepeatButton Name="PART_IncreaseButton" Background="{TemplateBinding Background}">
+                    <RepeatButton Name="PART_IncreaseButton" Background="{TemplateBinding Background}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
                       <RepeatButton.Template>
                         <ControlTemplate>
                           <Grid>
@@ -125,7 +125,7 @@
                 <TickBar Name="RightTickBar" Placement="Right" Width="{DynamicResource SliderOutsideTickBarThemeHeight}" HorizontalAlignment="Left" Margin="4,0,0,0" Grid.Column="2" Grid.RowSpan="3" />
                 <Track Name="PART_Track" Grid.Column="1" Grid.ColumnSpan="1" Grid.RowSpan="3" Orientation="Vertical">
                   <Track.DecreaseButton>
-                    <RepeatButton Name="PART_DecreaseButton" Background="{TemplateBinding Foreground}">
+                    <RepeatButton Name="PART_DecreaseButton" Background="{TemplateBinding Foreground}" VerticalAlignment="Stretch" HorizontalAlignment="Stretch">
                       <RepeatButton.Template>
                         <ControlTemplate>
                           <Grid>
@@ -137,7 +137,7 @@
                     </RepeatButton>
                   </Track.DecreaseButton>
                   <Track.IncreaseButton>
-                    <RepeatButton Name="PART_IncreaseButton" Background="{TemplateBinding Background}">
+                    <RepeatButton Name="PART_IncreaseButton" Background="{TemplateBinding Background}" VerticalAlignment="Stretch" HorizontalAlignment="Stretch">
                       <RepeatButton.Template>
                         <ControlTemplate>
                           <Grid>