diff --git a/src/HotChocolate/Primitives/src/Primitives/Utilities/NameUtils.cs b/src/HotChocolate/Primitives/src/Primitives/Utilities/NameUtils.cs
index 35c6e538c2f..d11457652ef 100644
--- a/src/HotChocolate/Primitives/src/Primitives/Utilities/NameUtils.cs
+++ b/src/HotChocolate/Primitives/src/Primitives/Utilities/NameUtils.cs
@@ -147,7 +147,7 @@ public static bool IsValidGraphQLName(this in ReadOnlySpan<byte> name)
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static bool IsLetterOrDigitOrUnderscore(this char c)
-        => IsLetterOrDigitOrUnderscore((byte)c);
+        => c is >= 'a' and <= 'z' or >= 'A' and <= 'Z' or >= '0' and <= '9' or '_';
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static bool IsLetterOrDigitOrUnderscore(this byte c)
@@ -188,5 +188,5 @@ private static bool IsLetterOrUnderscore(this byte c)
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static bool IsLetterOrUnderscore(this char c)
-        => IsLetterOrUnderscore((byte)c);
+        => c is >= 'a' and <= 'z' or >= 'A' and <= 'Z' or '_';
 }
diff --git a/src/HotChocolate/Primitives/test/Primitives.Tests/NameUtilsTests.cs b/src/HotChocolate/Primitives/test/Primitives.Tests/NameUtilsTests.cs
index 05ee5705fa1..3b774a02a92 100644
--- a/src/HotChocolate/Primitives/test/Primitives.Tests/NameUtilsTests.cs
+++ b/src/HotChocolate/Primitives/test/Primitives.Tests/NameUtilsTests.cs
@@ -10,6 +10,9 @@ public class NameUtilsTests
     [InlineData("1_Bar")]
     [InlineData("B/ar")]
     [InlineData("B+ar")]
+    [InlineData("Łar")]
+    [InlineData("Bŗar")]
+    [InlineData("Bİar")]
     public void InvalidName(string name)
     {
         var message = Assert.Throws<ArgumentException>(() => name.EnsureGraphQLName()).Message;
@@ -33,4 +36,19 @@ public void ValidName(string name)
     {
         name.EnsureGraphQLName();
     }
+
+    [Theory]
+    [InlineData("Łar", "_ar")]
+    [InlineData("Bŗar", "B_ar")]
+    [InlineData("Bİar", "B_ar")]
+    public void MakeValidGraphQLName_Should_ReplaceTheCharacter_When_ItIsNotAnAsciiNameCharacter(
+        string name,
+        string expected)
+    {
+        // act
+        var result = NameUtils.MakeValidGraphQLName(name);
+
+        // assert
+        Assert.Equal(expected, result);
+    }
 }