diff --git a/Services/ServerSettingsService.cs b/Services/ServerSettingsService.cs
index 2c1da2b..a4c91d4 100644
--- a/Services/ServerSettingsService.cs
+++ b/Services/ServerSettingsService.cs
@@ -77,12 +77,34 @@ public class ServerSettingsService
         }
     }
 
+    /// <summary>
+    /// Entfernt veraltete Settings aus der DB die nicht mehr in Definitions existieren.
+    /// </summary>
+    private void CleanupObsoleteSettings()
+    {
+        var obsoleteKeys = new[] { "ScanIntervalHours" };
+        using var conn = new SqliteConnection($"Data Source={_dbPath}");
+        conn.Open();
+        foreach (var key in obsoleteKeys)
+        {
+            using var cmd = conn.CreateCommand();
+            cmd.CommandText = "DELETE FROM server_settings WHERE key = @key";
+            cmd.Parameters.AddWithValue("@key", key);
+            cmd.ExecuteNonQuery();
+        }
+        lock (_lock)
+        {
+            foreach (var key in obsoleteKeys) _cache.Remove(key);
+        }
+    }
+
     /// <summary>
     /// Migriert bestehende Werte aus appsettings.Production.json in die DB (einmalig).
     /// Nur Settings die noch NICHT in der DB sind werden übernommen.
     /// </summary>
     public void MigrateFromAppSettings(string contentRootPath)
     {
+        CleanupObsoleteSettings();
         var prodPath = Path.Combine(contentRootPath, "appsettings.Production.json");
         if (!File.Exists(prodPath)) return;