diff --git a/lib/synth-audio.js b/lib/synth-audio.js
index a67c479..f5e812e 100644
--- a/lib/synth-audio.js
+++ b/lib/synth-audio.js
@@ -469,7 +469,7 @@ const synthGoogle = async(logger, {
   let sampleRate;
   if (isGemini || isVoiceCloning) {
     audioConfig = { audioEncoding: 'LINEAR16', sampleRateHertz: 24000 };
-    extension = 'r24';
+    extension = 'wav';
     sampleRate = 24000;
   } else {
     audioConfig = { audioEncoding: 'MP3' };