diff --git a/src/Perspex.Diagnostics/Views/LogicalTreeView.cs b/src/Perspex.Diagnostics/Views/LogicalTreeView.cs
index 276506bf09..21038ad50f 100644
--- a/src/Perspex.Diagnostics/Views/LogicalTreeView.cs
+++ b/src/Perspex.Diagnostics/Views/LogicalTreeView.cs
@@ -54,8 +54,9 @@ namespace Perspex.Diagnostics.Views
                     }),
                     new GridSplitter
                     {
-                        [Grid.ColumnProperty] = 1,
                         Width = 4,
+                        Orientation = Orientation.Vertical,
+                        [Grid.ColumnProperty] = 1,
                     },
                     new ContentControl
                     {
diff --git a/src/Perspex.Diagnostics/Views/VisualTreeView.cs b/src/Perspex.Diagnostics/Views/VisualTreeView.cs
index df7277e396..4b187d00a0 100644
--- a/src/Perspex.Diagnostics/Views/VisualTreeView.cs
+++ b/src/Perspex.Diagnostics/Views/VisualTreeView.cs
@@ -55,8 +55,9 @@ namespace Perspex.Diagnostics.Views
                     }),
                     new GridSplitter
                     {
-                        [Grid.ColumnProperty] = 1,
                         Width = 4,
+                        Orientation = Orientation.Vertical,
+                        [Grid.ColumnProperty] = 1,
                     },
                     new ContentControl
                     {