diff --git a/src/Adapter/MSTestAdapter.PlatformServices/Utilities/DeploymentItemUtility.cs b/src/Adapter/MSTestAdapter.PlatformServices/Utilities/DeploymentItemUtility.cs
index 867f593dae..07479ffe20 100644
--- a/src/Adapter/MSTestAdapter.PlatformServices/Utilities/DeploymentItemUtility.cs
+++ b/src/Adapter/MSTestAdapter.PlatformServices/Utilities/DeploymentItemUtility.cs
@@ -79,7 +79,7 @@ internal IList<DeploymentItem> GetClassLevelDeploymentItems(Type type, ICollecti
     /// <param name="warning"> The warning message if it is an invalid deployment item. </param>
     /// <returns> Returns true if it is a valid deployment item. </returns>
     [SuppressMessage("Microsoft.Design", "CA1021:AvoidOutParameters", MessageId = "2#", Justification = "Internal method.")]
-    internal static bool IsValidDeploymentItem([NotNullWhen(true)] string? sourcePath, [NotNullWhen(true)] string? relativeOutputDirectory, out string warning)
+    internal static bool IsValidDeploymentItem([NotNullWhen(true)] string? sourcePath, [NotNullWhen(true)] string? relativeOutputDirectory, [NotNullWhen(false)] out string? warning)
     {
         if (StringEx.IsNullOrEmpty(sourcePath))
         {
@@ -105,7 +105,7 @@ internal static bool IsValidDeploymentItem([NotNullWhen(true)] string? sourcePat
             return false;
         }
 
-        warning = string.Empty;
+        warning = null;
         return true;
     }
 
diff --git a/test/UnitTests/MSTestAdapter.PlatformServices.UnitTests/Utilities/ns13DeploymentItemUtilityTests.cs b/test/UnitTests/MSTestAdapter.PlatformServices.UnitTests/Utilities/ns13DeploymentItemUtilityTests.cs
index 5f64b0a4ef..dea08157df 100644
--- a/test/UnitTests/MSTestAdapter.PlatformServices.UnitTests/Utilities/ns13DeploymentItemUtilityTests.cs
+++ b/test/UnitTests/MSTestAdapter.PlatformServices.UnitTests/Utilities/ns13DeploymentItemUtilityTests.cs
@@ -389,7 +389,7 @@ public void IsValidDeploymentItemShouldReturnTrueForAValidDeploymentItem()
     {
         Verify(DeploymentItemUtility.IsValidDeploymentItem(_defaultDeploymentItemPath, _defaultDeploymentItemOutputDirectory, out string warning));
 
-        Verify(string.Empty.Equals(warning, StringComparison.Ordinal));
+        Verify(warning is null);
     }
     #endregion