diff --git a/lib/synth-audio.js b/lib/synth-audio.js
index 6fdd5f9..7bd509f 100644
--- a/lib/synth-audio.js
+++ b/lib/synth-audio.js
@@ -190,7 +190,7 @@ async function synthAudio(client, logger, stats, { account_sid,
         }
         else {
           audioBuffer = await synthMicrosoft(logger, {credentials, stats, language, voice, text, deploymentId,
-            filePath});
+            filePath, renderForCaching});
         }
         break;
       case 'nuance':