diff --git a/Program.cs b/Program.cs
index 556a54e..51c9ec9 100644
--- a/Program.cs
+++ b/Program.cs
@@ -3,6 +3,7 @@ using System.IO;
 using System.Net;
 using System.Net.Http;
 using System.Runtime.InteropServices;
+using System.Text;
 using Gott.Endpoints;
 using Gott.Middleware;
 using Gott.Services;
@@ -13,6 +14,20 @@ using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.FileProviders;
 using Microsoft.Extensions.Hosting;
 
+// Auf Windows: Console-Codepage des Server-Prozesses auf UTF-8 erzwingen.
+// Wirkt prozess-global (Win32 SetConsoleOutputCP/SetConsoleCP) und wird von
+// direkt gestarteten Child-Prozessen geerbt – damit Tools/Sub-Prozesse, die
+// die Console-Codepage abfragen, UTF-8 als Output-Encoding nutzen.
+if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+{
+    try
+    {
+        Console.OutputEncoding = Encoding.UTF8;
+        Console.InputEncoding = Encoding.UTF8;
+    }
+    catch { /* In Service-Kontexten ohne Console kann das werfen – ignorieren. */ }
+}
+
 var builder = WebApplication.CreateBuilder(args);
 
 if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
diff --git a/Services/ClaudeCliService.cs b/Services/ClaudeCliService.cs
index 8df2771..f374d4a 100644
--- a/Services/ClaudeCliService.cs
+++ b/Services/ClaudeCliService.cs
@@ -337,7 +337,16 @@ public class ClaudeCliService
             await process.StandardInput.FlushAsync();
             process.StandardInput.Close();
 
-            using var reader = process.StandardOutput;
+            // Eigener StreamReader mit großem Buffer + explizit UTF-8 ohne BOM-Detection.
+            // Default-Reader (process.StandardOutput) nutzt nur 1 KB Buffer, was bei
+            // gefragmentierten Pipe-Reads zu zerschnittenen Multi-Byte-UTF-8-Sequenzen
+            // und damit zu �-Replacement-Chars für Umlaute/Em-Dashes führen kann.
+            using var reader = new StreamReader(
+                process.StandardOutput.BaseStream,
+                new UTF8Encoding(encoderShouldEmitUTF8Identifier: false),
+                detectEncodingFromByteOrderMarks: false,
+                bufferSize: 16384,
+                leaveOpen: false);
             string line;
             while ((line = await reader.ReadLineAsync(cancellationToken)) != null)
             {