diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ConvertTo-Html.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ConvertTo-Html.cs
index 2c530a8ab93..41dd159a3ba 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ConvertTo-Html.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ConvertTo-Html.cs
@@ -321,7 +321,7 @@ internal static class ConvertHTMLParameterDefinitionKeys
         /// <summary>
         /// This allows for @{e='foo';label='bar';alignment='center';width='20'}.
         /// </summary>
-        internal class ConvertHTMLExpressionParameterDefinition : CommandParameterDefinition
+        internal sealed class ConvertHTMLExpressionParameterDefinition : CommandParameterDefinition
         {
             protected override void SetEntries()
             {
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/Csv.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/Csv.cs
index 9590cd7c771..d0b9f91e7f7 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/Csv.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/Csv.cs
@@ -8,7 +8,7 @@ namespace Microsoft.PowerShell.Commands
     /// <summary>
     /// This class is used to parse CSV text.
     /// </summary>
-    internal class CSVHelper
+    internal sealed class CSVHelper
     {
         internal CSVHelper(char delimiter)
         {
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/CsvCommands.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/CsvCommands.cs
index 6297d9b1f38..414b472e640 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/CsvCommands.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/CsvCommands.cs
@@ -885,7 +885,7 @@ protected override void ProcessRecord()
     /// <summary>
     /// Helper class for Export-Csv and ConvertTo-Csv.
     /// </summary>
-    internal class ExportCsvHelper : IDisposable
+    internal sealed class ExportCsvHelper : IDisposable
     {
         private readonly char _delimiter;
         private readonly BaseCsvWritingCommand.QuoteKind _quoteKind;
@@ -1224,7 +1224,7 @@ public void Dispose()
     /// <summary>
     /// Helper class to import single CSV file.
     /// </summary>
-    internal class ImportCsvHelper
+    internal sealed class ImportCsvHelper
     {
         #region constructor
 
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/CustomSerialization.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/CustomSerialization.cs
index da4e4a1262a..f8a39cce096 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/CustomSerialization.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/CustomSerialization.cs
@@ -14,7 +14,7 @@ namespace System.Management.Automation
     /// <summary>
     /// This class provides functionality for serializing a PSObject.
     /// </summary>
-    internal class CustomSerialization
+    internal sealed class CustomSerialization
     {
         #region constructor
         /// <summary>
@@ -179,8 +179,7 @@ internal void Stop()
     /// <summary>
     /// This internal helper class provides methods for serializing mshObject.
     /// </summary>
-    internal class
-    CustomInternalSerializer
+    internal sealed class CustomInternalSerializer
     {
         #region constructor
 
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/ExpressionColumnInfo.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/ExpressionColumnInfo.cs
index e905f5d64b6..4d0c8af875c 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/ExpressionColumnInfo.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/ExpressionColumnInfo.cs
@@ -6,7 +6,7 @@
 
 namespace Microsoft.PowerShell.Commands
 {
-    internal class ExpressionColumnInfo : ColumnInfo
+    internal sealed class ExpressionColumnInfo : ColumnInfo
     {
         private readonly PSPropertyExpression _expression;
 
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/HeaderInfo.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/HeaderInfo.cs
index d811ce32303..4f4e84a1569 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/HeaderInfo.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/HeaderInfo.cs
@@ -7,7 +7,7 @@
 
 namespace Microsoft.PowerShell.Commands
 {
-    internal class HeaderInfo
+    internal sealed class HeaderInfo
     {
         private readonly List<ColumnInfo> _columns = new();
 
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/OriginalColumnInfo.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/OriginalColumnInfo.cs
index 974188c2f74..4ec5e2240fa 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/OriginalColumnInfo.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/OriginalColumnInfo.cs
@@ -9,7 +9,7 @@
 
 namespace Microsoft.PowerShell.Commands
 {
-    internal class OriginalColumnInfo : ColumnInfo
+    internal sealed class OriginalColumnInfo : ColumnInfo
     {
         private readonly string _liveObjectPropertyName;
         private readonly OutGridViewCommand _parentCmdlet;
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/OutGridViewCommand.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/OutGridViewCommand.cs
index 43e24e8b5b6..574ca39426d 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/OutGridViewCommand.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/OutGridViewCommand.cs
@@ -323,7 +323,7 @@ internal static GridHeader ConstructGridHeader(PSObject input, OutGridViewComman
             internal abstract void ProcessInputObject(PSObject input);
         }
 
-        internal class ScalarTypeHeader : GridHeader
+        internal sealed class ScalarTypeHeader : GridHeader
         {
             private readonly Type _originalScalarType;
 
@@ -349,7 +349,7 @@ internal override void ProcessInputObject(PSObject input)
             }
         }
 
-        internal class NonscalarTypeHeader : GridHeader
+        internal sealed class NonscalarTypeHeader : GridHeader
         {
             private readonly AppliesTo _appliesTo = null;
 
@@ -453,7 +453,7 @@ internal override void ProcessInputObject(PSObject input)
             }
         }
 
-        internal class HeteroTypeHeader : GridHeader
+        internal sealed class HeteroTypeHeader : GridHeader
         {
             internal HeteroTypeHeader(OutGridViewCommand parentCmd, PSObject input) : base(parentCmd)
             {
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/OutWindowProxy.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/OutWindowProxy.cs
index b406c2bc78c..ef9b0528c75 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/OutWindowProxy.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/OutWindowProxy.cs
@@ -13,7 +13,7 @@
 
 namespace Microsoft.PowerShell.Commands
 {
-    internal class OutWindowProxy : IDisposable
+    internal sealed class OutWindowProxy : IDisposable
     {
         private const string OutGridViewWindowClassName = "Microsoft.Management.UI.Internal.OutGridViewWindow";
         private const string OriginalTypePropertyName = "OriginalType";
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/ScalarTypeColumnInfo.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/ScalarTypeColumnInfo.cs
index 77f80c269a3..38cc9668856 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/ScalarTypeColumnInfo.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/ScalarTypeColumnInfo.cs
@@ -6,7 +6,7 @@
 
 namespace Microsoft.PowerShell.Commands
 {
-    internal class ScalarTypeColumnInfo : ColumnInfo
+    internal sealed class ScalarTypeColumnInfo : ColumnInfo
     {
         private readonly Type _type;
 
@@ -29,7 +29,7 @@ internal override object GetValue(PSObject liveObject)
         }
     }
 
-    internal class TypeNameColumnInfo : ColumnInfo
+    internal sealed class TypeNameColumnInfo : ColumnInfo
     {
         internal TypeNameColumnInfo(string staleObjectPropertyName, string displayName)
             : base(staleObjectPropertyName, displayName)
@@ -43,7 +43,7 @@ internal override object GetValue(PSObject liveObject)
         }
     }
 
-    internal class ToStringColumnInfo : ColumnInfo
+    internal sealed class ToStringColumnInfo : ColumnInfo
     {
         private readonly OutGridViewCommand _parentCmdlet;
 
@@ -60,7 +60,7 @@ internal override object GetValue(PSObject liveObject)
         }
     }
 
-    internal class IndexColumnInfo : ColumnInfo
+    internal sealed class IndexColumnInfo : ColumnInfo
     {
         private int _index = 0;
 
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/TableView.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/TableView.cs
index 9213484d332..e152bb7c973 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/TableView.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/OutGridView/TableView.cs
@@ -12,7 +12,7 @@
 
 namespace Microsoft.PowerShell.Commands
 {
-    internal class TableView
+    internal sealed class TableView
     {
         private PSPropertyExpressionFactory _expressionFactory;
         private TypeInfoDataBase _typeInfoDatabase;
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/GetRandomCommandBase.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/GetRandomCommandBase.cs
index 7d6e4e71e67..fef7764c5b8 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/GetRandomCommandBase.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/GetRandomCommandBase.cs
@@ -561,7 +561,7 @@ protected override void EndProcessing()
     /// methods using the NextBytes() primitive based on the CLR implementation:
     ///     https://referencesource.microsoft.com/#mscorlib/system/random.cs.
     /// </summary>
-    internal class PolymorphicRandomNumberGenerator
+    internal sealed class PolymorphicRandomNumberGenerator
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="PolymorphicRandomNumberGenerator"/> class.
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ImplicitRemotingCommands.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ImplicitRemotingCommands.cs
index 8142f682b36..16b7db47d41 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ImplicitRemotingCommands.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ImplicitRemotingCommands.cs
@@ -1916,7 +1916,7 @@ internal List<string> GenerateProxyModule(
         #endregion
     }
 
-    internal class ImplicitRemotingCodeGenerator
+    internal sealed class ImplicitRemotingCodeGenerator
     {
         internal static readonly Version VersionOfScriptWriter = new(1, 0);
 
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/JsonSchemaReferenceResolutionException.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/JsonSchemaReferenceResolutionException.cs
index ba664ccef1b..7c2a7ac65f4 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/JsonSchemaReferenceResolutionException.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/JsonSchemaReferenceResolutionException.cs
@@ -11,7 +11,7 @@ namespace Microsoft.PowerShell.Commands;
 /// Thrown during evaluation of <see cref="TestJsonCommand"/> when an attempt
 /// to resolve a <code>$ref</code> or <code>$dynamicRef</code> fails.
 /// </summary>
-internal class JsonSchemaReferenceResolutionException : Exception
+internal sealed class JsonSchemaReferenceResolutionException : Exception
 {
     /// <summary>
     /// Initializes a new instance of the <see cref="JsonSchemaReferenceResolutionException"/> class.
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ObjectCommandComparer.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ObjectCommandComparer.cs
index bb71dfdbe1c..fd01768d5a8 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ObjectCommandComparer.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ObjectCommandComparer.cs
@@ -19,7 +19,7 @@ namespace Microsoft.PowerShell.Commands
     /// isExistingProperty is needed to distinguish whether a property exists and its value is null or
     /// the property does not exist at all.
     /// </summary>
-    internal class ObjectCommandPropertyValue
+    internal sealed class ObjectCommandPropertyValue
     {
         private ObjectCommandPropertyValue() { }
 
@@ -136,7 +136,7 @@ public override int GetHashCode()
     /// <summary>
     /// ObjectCommandComparer class.
     /// </summary>
-    internal class ObjectCommandComparer : IComparer
+    internal sealed class ObjectCommandComparer : IComparer
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="ObjectCommandComparer"/> class.
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/OrderObjectBase.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/OrderObjectBase.cs
index 519b472620b..178eaa12f62 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/OrderObjectBase.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/OrderObjectBase.cs
@@ -24,7 +24,7 @@ internal static class SortObjectParameterDefinitionKeys
 
     /// <summary>
     /// </summary>
-    internal class SortObjectExpressionParameterDefinition : CommandParameterDefinition
+    internal sealed class SortObjectExpressionParameterDefinition : CommandParameterDefinition
     {
         protected override void SetEntries()
         {
@@ -36,7 +36,7 @@ protected override void SetEntries()
 
     /// <summary>
     /// </summary>
-    internal class GroupObjectExpressionParameterDefinition : CommandParameterDefinition
+    internal sealed class GroupObjectExpressionParameterDefinition : CommandParameterDefinition
     {
         protected override void SetEntries()
         {
@@ -630,7 +630,7 @@ internal sealed class OrderByPropertyEntry
         internal bool comparable = false;
     }
 
-    internal class OrderByPropertyComparer : IComparer<OrderByPropertyEntry>
+    internal sealed class OrderByPropertyComparer : IComparer<OrderByPropertyEntry>
     {
         internal OrderByPropertyComparer(bool[] ascending, CultureInfo cultureInfo, bool caseSensitive)
         {
@@ -699,7 +699,7 @@ internal static OrderByPropertyComparer CreateComparer(List<OrderByPropertyEntry
         private readonly ObjectCommandComparer[] _propertyComparers = null;
     }
 
-    internal class IndexedOrderByPropertyComparer : IComparer<OrderByPropertyEntry>
+    internal sealed class IndexedOrderByPropertyComparer : IComparer<OrderByPropertyEntry>
     {
         internal IndexedOrderByPropertyComparer(OrderByPropertyComparer orderByPropertyComparer)
         {
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/Select-Object.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/Select-Object.cs
index efd7007e131..9db27335da5 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/Select-Object.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/Select-Object.cs
@@ -53,7 +53,7 @@ internal bool IsMatch(PSPropertyExpression expression)
         private readonly WildcardPattern[] _wildcardPatterns;
     }
 
-    internal class SelectObjectExpressionParameterDefinition : CommandParameterDefinition
+    internal sealed class SelectObjectExpressionParameterDefinition : CommandParameterDefinition
     {
         protected override void SetEntries()
         {
@@ -866,7 +866,7 @@ protected override void EndProcessing()
     [SuppressMessage("Microsoft.Usage", "CA2237:MarkISerializableTypesWithSerializable", Justification = "This exception is internal and never thrown by any public API")]
     [SuppressMessage("Microsoft.Design", "CA1032:ImplementStandardExceptionConstructors", Justification = "This exception is internal and never thrown by any public API")]
     [SuppressMessage("Microsoft.Design", "CA1064:ExceptionsShouldBePublic", Justification = "This exception is internal and never thrown by any public API")]
-    internal class SelectObjectException : SystemException
+    internal sealed class SelectObjectException : SystemException
     {
         internal ErrorRecord ErrorRecord { get; }
 
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ShowCommand/ShowCommandProxy.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ShowCommand/ShowCommandProxy.cs
index a8a9c8f194d..ab8909bb590 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ShowCommand/ShowCommandProxy.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/ShowCommand/ShowCommandProxy.cs
@@ -16,7 +16,7 @@ namespace Microsoft.PowerShell.Commands
     /// Help show-command create WPF object and invoke WPF windows with the
     /// Microsoft.PowerShell.Commands.ShowCommandInternal.ShowCommandHelperhelp type defined in Microsoft.PowerShell.GraphicalHost.dll.
     /// </summary>
-    internal class ShowCommandProxy
+    internal sealed class ShowCommandProxy
     {
         private const string ShowCommandHelperName = "Microsoft.PowerShell.Commands.ShowCommandInternal.ShowCommandHelper";
 
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/Common/InvokeRestMethodCommand.Common.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/Common/InvokeRestMethodCommand.Common.cs
index eafdaadbede..22ffaef288c 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/Common/InvokeRestMethodCommand.Common.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/Common/InvokeRestMethodCommand.Common.cs
@@ -354,7 +354,7 @@ public enum RestReturnType
             Xml,
         }
 
-        internal class BufferingStreamReader : Stream
+        internal sealed class BufferingStreamReader : Stream
         {
             internal BufferingStreamReader(Stream baseStream, TimeSpan perReadTimeout, CancellationToken cancellationToken)
             {
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/CoreCLR/WebProxy.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/CoreCLR/WebProxy.cs
index 6e9f6bdf98e..c7400e75f9d 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/CoreCLR/WebProxy.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/CoreCLR/WebProxy.cs
@@ -8,7 +8,7 @@
 
 namespace Microsoft.PowerShell.Commands
 {
-    internal class WebProxy : IWebProxy, IEquatable<WebProxy>
+    internal sealed class WebProxy : IWebProxy, IEquatable<WebProxy>
     {
         private ICredentials? _credentials;
         private readonly Uri _proxyAddress;
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/StreamHelper.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/StreamHelper.cs
index 52ff515b0b2..d24961834b6 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/StreamHelper.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/StreamHelper.cs
@@ -22,7 +22,7 @@ namespace Microsoft.PowerShell.Commands
     /// this class as a wrapper to MemoryStream to lazily initialize. Otherwise, the
     /// content will unnecessarily be read even if there are no consumers for it.
     /// </summary>
-    internal class WebResponseContentMemoryStream : MemoryStream
+    internal sealed class WebResponseContentMemoryStream : MemoryStream
     {
         #region Data
 
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/XmlCommands.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/XmlCommands.cs
index 6157849eeec..6473d6d4fae 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/XmlCommands.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/XmlCommands.cs
@@ -715,7 +715,7 @@ protected override void ProcessRecord()
     /// <summary>
     /// Helper class to import single XML file.
     /// </summary>
-    internal class ImportXmlHelper : IDisposable
+    internal sealed class ImportXmlHelper : IDisposable
     {
         #region constructor
 
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/trace/MshHostTraceListener.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/trace/MshHostTraceListener.cs
index 357e0222b6d..b7e4ed279aa 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/trace/MshHostTraceListener.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/trace/MshHostTraceListener.cs
@@ -17,7 +17,7 @@ namespace Microsoft.PowerShell.Commands
     /// This trace listener cannot be specified in the app.config file.
     /// It must be added through the add-tracelistener cmdlet.
     /// </remarks>
-    internal class PSHostTraceListener
+    internal sealed class PSHostTraceListener
         : System.Diagnostics.TraceListener
     {
         #region TraceListener constructors and disposer
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/trace/TraceExpressionCommand.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/trace/TraceExpressionCommand.cs
index 91cb0d46abc..2bf7045cbed 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/trace/TraceExpressionCommand.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/trace/TraceExpressionCommand.cs
@@ -323,7 +323,7 @@ public void Dispose()
     /// cmdlet.  It gets attached to the sub-pipelines success or error pipeline and redirects
     /// all objects written to these pipelines to trace-command pipeline.
     /// </summary>
-    internal class TracePipelineWriter : PipelineWriter
+    internal sealed class TracePipelineWriter : PipelineWriter
     {
         internal TracePipelineWriter(
             TraceListenerCommandBase cmdlet,