diff --git a/src/Docfx.Build.Common/Reference/OverwriteDocumentReader.cs b/src/Docfx.Build.Common/Reference/OverwriteDocumentReader.cs
index 591c6b3a2c2..540848fa225 100644
--- a/src/Docfx.Build.Common/Reference/OverwriteDocumentReader.cs
+++ b/src/Docfx.Build.Common/Reference/OverwriteDocumentReader.cs
@@ -12,7 +12,7 @@
 
 namespace Docfx.Build.Common;
 
-public class OverwriteDocumentReader
+public static class OverwriteDocumentReader
 {
     public static FileModel Read(FileAndType file)
     {
diff --git a/src/Docfx.Dotnet/Filters/RoslynFilterData.cs b/src/Docfx.Dotnet/Filters/RoslynFilterData.cs
index ee12d0fd40a..9025472374b 100644
--- a/src/Docfx.Dotnet/Filters/RoslynFilterData.cs
+++ b/src/Docfx.Dotnet/Filters/RoslynFilterData.cs
@@ -5,7 +5,7 @@
 
 namespace Docfx.Dotnet;
 
-internal class RoslynFilterData
+internal static class RoslynFilterData
 {
     public static SymbolFilterData GetSymbolFilterData(ISymbol symbol)
     {
diff --git a/src/Docfx.Dotnet/ManagedReference/Visitors/SpecIdHelper.cs b/src/Docfx.Dotnet/ManagedReference/Visitors/SpecIdHelper.cs
index 6c728817d0c..a294d8925fb 100644
--- a/src/Docfx.Dotnet/ManagedReference/Visitors/SpecIdHelper.cs
+++ b/src/Docfx.Dotnet/ManagedReference/Visitors/SpecIdHelper.cs
@@ -7,7 +7,7 @@
 
 namespace Docfx.Dotnet;
 
-internal sealed class SpecIdHelper
+internal static class SpecIdHelper
 {
     private static readonly Regex TypeParameterRegex = new(@"\B(?<!`)`\d+", RegexOptions.Compiled);
     private static readonly Regex MethodParameterRegex = new(@"\B``\d+", RegexOptions.Compiled);
@@ -82,7 +82,7 @@ private static string SpecMethodGenericParameter(IReadOnlyList<string> names, st
     }
 
     /// <summary>
-    /// spec extension method's receiver type. 
+    /// spec extension method's receiver type.
     /// for below overload: M(this A), M(this A, A), AddReference applies to the first method and AddSpecReference applies to the second method might get same id without prepending receiver type.
     /// </summary>
     /// <param name="symbol">symbol</param>