diff --git a/lib/synth-audio.js b/lib/synth-audio.js
index 89ab5d7..0e3b274 100644
--- a/lib/synth-audio.js
+++ b/lib/synth-audio.js
@@ -86,7 +86,7 @@ const trimTrailingSilence = (buffer) => {
  */
 async function synthAudio(client, createHash, retrieveHash, logger, stats, { account_sid,
   vendor, language, voice, gender, text, engine, salt, model, credentials, deploymentId,
-  disableTtsCache, renderForCaching, disableTtsStreaming, options, preCache = false
+  disableTtsCache, renderForCaching = false, disableTtsStreaming, options
 }) {
   let audioBuffer;
   let servedFromCache = false;
@@ -165,7 +165,7 @@ async function synthAudio(client, createHash, retrieveHash, logger, stats, { acc
     voice: voice || deploymentId,
     engine,
     text,
-    preCache: true
+    renderForCaching: true
   });
 
   const key = makeSynthKey({
@@ -175,10 +175,10 @@ async function synthAudio(client, createHash, retrieveHash, logger, stats, { acc
     voice: voice || deploymentId,
     engine,
     text,
-    preCache
+    renderForCaching
   });
   let filePath;
-  filePath = makeFilePath({vendor, key, salt, preCache});
+  filePath = makeFilePath({vendor, key, salt, renderForCaching});
   debug(`synth key is ${key}`);
   let cached;
   if (!disableTtsCache) {
@@ -187,7 +187,7 @@ async function synthAudio(client, createHash, retrieveHash, logger, stats, { acc
     cached = await client.get(preCachekey);
     if (cached) {
       // Precache audio is available update filpath with precache file extension.
-      filePath = makeFilePath({vendor, key, salt, preCache: true});
+      filePath = makeFilePath({vendor, key, salt, renderForCaching: true});
     } else {
       cached = await client.get(key);
     }
diff --git a/lib/utils.js b/lib/utils.js
index 0390910..9d088c1 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -18,29 +18,29 @@ const debug = require('debug')('jambonz:realtimedb-helpers');
 
 function makeSynthKey({
   account_sid = '', vendor, language, voice, engine = '', text,
-  preCache = false}) {
+  renderForCaching = false}) {
   const hash = crypto.createHash('sha1');
   hash.update(`${language}:${vendor}:${voice}:${engine}:${text}`);
   const hexHashKey = hash.digest('hex');
   const accountKey = account_sid ? `:${account_sid}` : '';
-  const namespace = vendor.startsWith('custom') ? vendor : getFileExtension({vendor, preCache});
+  const namespace = vendor.startsWith('custom') ? vendor : getFileExtension({vendor, renderForCaching});
   const key = `tts${accountKey}:${namespace}:${hexHashKey}`;
   return key;
 }
 
-function makeFilePath({vendor, key, salt = '', preCache = false}) {
-  const extension = getFileExtension({vendor, preCache});
+function makeFilePath({vendor, key, salt = '', renderForCaching = false}) {
+  const extension = getFileExtension({vendor, renderForCaching});
   return `${TMP_FOLDER}/${key.replace('tts:', `tts-${salt}`)}.${extension}`;
 }
 
-function getFileExtension({vendor, preCache = false}) {
+function getFileExtension({vendor, renderForCaching = false}) {
   const mp3Extension = 'mp3';
   const r8Extension = 'r8';
 
   switch (vendor) {
     case 'azure':
     case 'microsoft':
-      if (!preCache && !JAMBONES_DISABLE_TTS_STREAMING || JAMBONES_TTS_TRIM_SILENCE) {
+      if (!renderForCaching && !JAMBONES_DISABLE_TTS_STREAMING || JAMBONES_TTS_TRIM_SILENCE) {
         return r8Extension;
       } else {
         return mp3Extension;
@@ -48,7 +48,7 @@ function getFileExtension({vendor, preCache = false}) {
     case 'deepgram':
     case 'elevenlabs':
     case 'rimlabs':
-      if (!preCache && !JAMBONES_DISABLE_TTS_STREAMING) {
+      if (!renderForCaching && !JAMBONES_DISABLE_TTS_STREAMING) {
         return r8Extension;
       } else {
         return mp3Extension;