diff --git a/src/services/windows-media-tts.ts b/src/services/windows-media-tts.ts
index 85fc010..496ef8a 100644
--- a/src/services/windows-media-tts.ts
+++ b/src/services/windows-media-tts.ts
@@ -25,12 +25,16 @@ function windowsMediaPreamble(): string {
     "Add-Type -AssemblyName System.Runtime.WindowsRuntime;",
     "$null = [Windows.Media.SpeechSynthesis.SpeechSynthesizer, Windows.Media.SpeechSynthesis, ContentType=WindowsRuntime];",
     "$null = [Windows.Storage.Streams.DataReader, Windows.Storage.Streams, ContentType=WindowsRuntime];",
+    "$null = [Windows.Foundation.AsyncStatus, Windows.Foundation, ContentType=WindowsRuntime];",
     "function Await-WinRt($operation) {",
-    "  $method = [System.WindowsRuntimeSystemExtensions].GetMethods() | Where-Object { $_.Name -eq 'AsTask' -and $_.IsGenericMethod -and $_.GetParameters().Count -eq 1 } | Select-Object -First 1;",
-    "  if (-not $method) { throw 'System.WindowsRuntimeSystemExtensions.AsTask 를 찾지 못했습니다.' }",
-    "  $resultType = $operation.GetType().GenericTypeArguments[0];",
-    "  $task = $method.MakeGenericMethod($resultType).Invoke($null, @($operation));",
-    "  return $task.GetAwaiter().GetResult();",
+    "  while ($operation.Status -eq [Windows.Foundation.AsyncStatus]::Started) { Start-Sleep -Milliseconds 10 }",
+    "  if ($operation.Status -eq [Windows.Foundation.AsyncStatus]::Completed) { return $operation.GetResults() }",
+    "  if ($operation.Status -eq [Windows.Foundation.AsyncStatus]::Canceled) { throw 'WinRT async operation canceled.' }",
+    "  if ($operation.Status -eq [Windows.Foundation.AsyncStatus]::Error) {",
+    "    if ($operation.ErrorCode) { throw $operation.ErrorCode }",
+    "    throw 'WinRT async operation failed.'",
+    "  }",
+    "  throw ('Unexpected WinRT async status: ' + [string]$operation.Status)",
     "}",
   ].join(" ");
 }