diff --git a/src/Lua/CodeAnalysis/Compilation/BomUtility.cs b/src/Lua/CodeAnalysis/Compilation/BomUtility.cs
index 58ae3720..d80dd4d4 100644
--- a/src/Lua/CodeAnalysis/Compilation/BomUtility.cs
+++ b/src/Lua/CodeAnalysis/Compilation/BomUtility.cs
@@ -2,7 +2,7 @@
 
 namespace Lua.CodeAnalysis.Compilation;
 
-public static class BomUtility
+internal static class BomUtility
 {
     static ReadOnlySpan<byte> BomUtf8 => [0xEF, 0xBB, 0xBF];
     static ReadOnlySpan<byte> BomUtf16Little => [0xFF, 0xFE];
diff --git a/src/Lua/Standard/Internal/LuaPlatformUtility.cs b/src/Lua/Standard/Internal/LuaPlatformUtility.cs
index b310c8d4..1c3365af 100644
--- a/src/Lua/Standard/Internal/LuaPlatformUtility.cs
+++ b/src/Lua/Standard/Internal/LuaPlatformUtility.cs
@@ -1,6 +1,6 @@
 namespace Lua.Standard.Internal;
 
-public class LuaPlatformUtility
+internal class LuaPlatformUtility
 {
     public static bool IsSandBox => SupportStdio;
     public static bool SupportStdio => _supportStdioTryLazy.Value;