diff --git a/lib/utils.js b/lib/utils.js
index 9d088c1..19c8004 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -48,6 +48,8 @@ function getFileExtension({vendor, renderForCaching = false}) {
     case 'deepgram':
     case 'elevenlabs':
     case 'rimlabs':
+    case 'playht':
+    case vendor.startsWith('custom') ? vendor : 'cant_match_value':
       if (!renderForCaching && !JAMBONES_DISABLE_TTS_STREAMING) {
         return r8Extension;
       } else {