diff --git a/AyCode.Core.Serializers.Console/AyCode.Core.Serializers.Console.csproj b/AyCode.Core.Serializers.Console/AyCode.Core.Serializers.Console.csproj
index 352bf54..4c4bf12 100644
--- a/AyCode.Core.Serializers.Console/AyCode.Core.Serializers.Console.csproj
+++ b/AyCode.Core.Serializers.Console/AyCode.Core.Serializers.Console.csproj
@@ -16,8 +16,6 @@
 		<TargetFramework>net9.0</TargetFramework>
 		<ImplicitUsings>enable</ImplicitUsings>
 		<Nullable>enable</Nullable>
-
-		<JsonSerializerIsReflectionEnabledByDefault>true</JsonSerializerIsReflectionEnabledByDefault>
 	</PropertyGroup>
 
 	<!-- AOT-mode is publish-time only.
@@ -47,6 +45,8 @@
 		     Suppress for now so builds succeed; revisit if AOT runtime issues surface beyond ctor metadata. -->
 		<SuppressTrimAnalysisWarnings>true</SuppressTrimAnalysisWarnings>
 		<TrimmerSingleWarn>false</TrimmerSingleWarn>
+
+		<JsonSerializerIsReflectionEnabledByDefault>true</JsonSerializerIsReflectionEnabledByDefault>
 	</PropertyGroup>
 
 </Project>
diff --git a/AyCode.Core/Serializers/Binaries/AcBinarySerializer.BinarySerializationContext.cs b/AyCode.Core/Serializers/Binaries/AcBinarySerializer.BinarySerializationContext.cs
index f2c8bf2..07d6ec5 100644
--- a/AyCode.Core/Serializers/Binaries/AcBinarySerializer.BinarySerializationContext.cs
+++ b/AyCode.Core/Serializers/Binaries/AcBinarySerializer.BinarySerializationContext.cs
@@ -699,21 +699,25 @@ public static partial class AcBinarySerializer
 
         public void WriteFixStrDirect(string value)
         {
-            var length = value.Length;
-            EnsureCapacity(1 + length);
-
-            var destSpan = _buffer.AsSpan(_position + 1, length);
-            var status = Ascii.FromUtf16(value.AsSpan(), destSpan, out var bytesWritten);
-
-            if (status == OperationStatus.Done && bytesWritten == length)
+            // Compute UTF-8 byte count up front. FixStr opcode encodes byte count (5-bit field, ≤31).
+            // For ASCII: byte count = char count; for non-ASCII: byte count > char count.
+            // Bonus over the prior ASCII-only path: short non-ASCII strings (e.g. 8-char Hungarian
+            // ≈ 12 bytes) now also fit in FixStr and save the String-marker + VarUInt overhead.
+            var byteCount = Utf8NoBom.GetByteCount(value);
+            if (byteCount <= BinaryTypeCode.FixStrMaxLength)
             {
-                _buffer[_position] = BinaryTypeCode.EncodeFixStr(length);
-                _position += 1 + length;
+                EnsureCapacity(1 + byteCount);
+                _buffer[_position++] = BinaryTypeCode.EncodeFixStr(byteCount);
+                Utf8NoBom.GetBytes(value.AsSpan(), _buffer.AsSpan(_position, byteCount));
+                _position += byteCount;
             }
             else
             {
                 _buffer[_position++] = BinaryTypeCode.String;
-                WriteStringUtf8Internal(value);
+                EnsureCapacity(VarUIntSize((uint)byteCount) + byteCount);
+                WriteVarUIntUnsafe((uint)byteCount);
+                Utf8NoBom.GetBytes(value.AsSpan(), _buffer.AsSpan(_position, byteCount));
+                _position += byteCount;
             }
         }