diff --git a/src/Esprima/Ast/ArrayPattern.cs b/src/Esprima/Ast/ArrayPattern.cs
index 6b81d11c..16a3b149 100644
--- a/src/Esprima/Ast/ArrayPattern.cs
+++ b/src/Esprima/Ast/ArrayPattern.cs
@@ -1,5 +1,4 @@
 using System.Runtime.CompilerServices;
-using Esprima.Utils;
 
 namespace Esprima.Ast;
 
diff --git a/src/Esprima/Ast/ExportDefaultDeclaration.cs b/src/Esprima/Ast/ExportDefaultDeclaration.cs
index 1d6ddff5..84429330 100644
--- a/src/Esprima/Ast/ExportDefaultDeclaration.cs
+++ b/src/Esprima/Ast/ExportDefaultDeclaration.cs
@@ -1,5 +1,4 @@
 using System.Runtime.CompilerServices;
-using Esprima.Utils;
 
 namespace Esprima.Ast;
 
diff --git a/src/Esprima/Character.cs b/src/Esprima/Character.cs
index 2af03b46..1b620af6 100644
--- a/src/Esprima/Character.cs
+++ b/src/Esprima/Character.cs
@@ -20,7 +20,7 @@ public static partial class Character
 
     // https://tc39.github.io/ecma262/#sec-line-terminators
 
-    public static bool IsLineTerminator(char ch)
+    internal static bool IsLineTerminator(char ch)
     {
         return ch == 10
                || ch == 13
@@ -31,29 +31,29 @@ public static bool IsLineTerminator(char ch)
 
     // https://tc39.github.io/ecma262/#sec-white-space
 
-    public static bool IsWhiteSpace(char ch)
+    internal static bool IsWhiteSpace(char ch)
     {
         return (_characterData[ch] & (byte) CharacterMask.WhiteSpace) != 0;
     }
 
     // https://tc39.github.io/ecma262/#sec-names-and-keywords
 
-    public static bool IsIdentifierStart(char ch)
+    internal static bool IsIdentifierStart(char ch)
     {
         return (_characterData[ch] & (byte) CharacterMask.IdentifierStart) != 0;
     }
 
-    public static bool IsIdentifierStart(string s, int index)
+    internal static bool IsIdentifierStart(string s, int index)
     {
         return IsIdentifierStartUnicodeCategory(CharUnicodeInfo.GetUnicodeCategory(s, index));
     }
 
-    public static bool IsIdentifierPart(char ch)
+    internal static bool IsIdentifierPart(char ch)
     {
         return (_characterData[ch] & (byte) CharacterMask.IdentifierPart) != 0;
     }
 
-    public static bool IsIdentifierPart(string s, int index)
+    internal static bool IsIdentifierPart(string s, int index)
     {
         return IsIdentifierPartUnicodeCategory(CharUnicodeInfo.GetUnicodeCategory(s, index));
     }
@@ -72,12 +72,11 @@ public static bool IsIdentifierPart(string s, int index)
 
     public static bool IsOctalDigit(char cp) => IsInRange(cp, '0', '7');
 
-    public static string FromCodePoint(int cp) => char.ConvertFromUtf32(cp);
+    internal static string FromCodePoint(int cp) => char.ConvertFromUtf32(cp);
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static bool IsInRange(char c, char min, char max) => c - (uint) min <= max - (uint) min;
 
-
     internal static bool IsIdentifierStartUnicodeCategory(UnicodeCategory cat)
     {
         return IsLetterChar(cat) || cat is UnicodeCategory.ModifierLetter or UnicodeCategory.NonSpacingMark;
diff --git a/src/Esprima/Messages.cs b/src/Esprima/Messages.cs
index d54f06ea..9b628cda 100644
--- a/src/Esprima/Messages.cs
+++ b/src/Esprima/Messages.cs
@@ -1,7 +1,7 @@
 namespace Esprima;
 
 // Error messages should be identical to V8.
-public static class Messages
+internal static class Messages
 {
     public const string ArgumentsNotAllowedInClassField = "'arguments' is not allowed in class field initializer or static initialization block";
     public const string AsyncFunctionInSingleStatementContext = "Async functions can only be declared at the top level or inside a block.";
diff --git a/src/Esprima/Utils/AstToJsonConverter.cs b/src/Esprima/Utils/AstToJsonConverter.cs
index 9528ba88..d0a3ccdd 100644
--- a/src/Esprima/Utils/AstToJsonConverter.cs
+++ b/src/Esprima/Utils/AstToJsonConverter.cs
@@ -1,5 +1,4 @@
-using System;
-using System.Collections;
+using System.Collections;
 using System.Globalization;
 using System.Numerics;
 using System.Reflection;