diff --git a/src/System.Windows.Forms.Design/tests/UnitTests/System/Windows/Forms/Design/ToolStripContentPanelDesignerTests.cs b/src/System.Windows.Forms.Design/tests/UnitTests/System/Windows/Forms/Design/ToolStripContentPanelDesignerTests.cs
index 3da88318ee9..59d1cc85f85 100644
--- a/src/System.Windows.Forms.Design/tests/UnitTests/System/Windows/Forms/Design/ToolStripContentPanelDesignerTests.cs
+++ b/src/System.Windows.Forms.Design/tests/UnitTests/System/Windows/Forms/Design/ToolStripContentPanelDesignerTests.cs
@@ -36,7 +36,7 @@ public void SnapLines_ShouldReturnNonNullList()
     [Fact]
     public void SnapLines_ShouldCallAddPaddingSnapLines()
     {
-        string[] paddingFilters = [SnapLine.PaddingLeft, SnapLine.PaddingRight, SnapLine.PaddingTop, SnapLine.PaddingBottom];
+        string?[] paddingFilters = [SnapLine.PaddingLeft, SnapLine.PaddingRight, SnapLine.PaddingTop, SnapLine.PaddingBottom];
 
         List<SnapLine> snapLines = _toolStripContentPanelDesigner.SnapLines.Cast<SnapLine>().ToList();