diff --git a/packages/google-cloud-texttospeech/protos/protos.js b/packages/google-cloud-texttospeech/protos/protos.js
index 3ac80b050ef..9986eed192f 100644
--- a/packages/google-cloud-texttospeech/protos/protos.js
+++ b/packages/google-cloud-texttospeech/protos/protos.js
@@ -28,7 +28,7 @@
     var $Reader = $protobuf.Reader, $Writer = $protobuf.Writer, $util = $protobuf.util;
     
     // Exported root namespace
-    var $root = $protobuf.roots._google_cloud_text_to_speech_2_3_0_protos || ($protobuf.roots._google_cloud_text_to_speech_2_3_0_protos = {});
+    var $root = $protobuf.roots._google_cloud_text_to_speech_protos || ($protobuf.roots._google_cloud_text_to_speech_protos = {});
     
     $root.google = (function() {
     
diff --git a/packages/google-cloud-texttospeech/src/v1/text_to_speech_client.ts b/packages/google-cloud-texttospeech/src/v1/text_to_speech_client.ts
index 30b09da205b..46e9ef42b53 100644
--- a/packages/google-cloud-texttospeech/src/v1/text_to_speech_client.ts
+++ b/packages/google-cloud-texttospeech/src/v1/text_to_speech_client.ts
@@ -89,6 +89,13 @@ export class TextToSpeechClient {
     }
     opts.servicePath = opts.servicePath || servicePath;
     opts.port = opts.port || port;
+
+    // users can override the config from client side, like retry codes name.
+    // The detailed structure of the clientConfig can be found here: https://github.com/googleapis/gax-nodejs/blob/master/src/gax.ts#L546
+    // The way to override client config for Showcase API:
+    //
+    // const customConfig = {"interfaces": {"google.showcase.v1beta1.Echo": {"methods": {"Echo": {"retry_codes_name": "idempotent", "retry_params_name": "default"}}}}}
+    // const showcaseClient = new showcaseClient({ projectId, customConfig });
     opts.clientConfig = opts.clientConfig || {};
 
     const isBrowser = typeof window !== 'undefined';
diff --git a/packages/google-cloud-texttospeech/src/v1beta1/text_to_speech_client.ts b/packages/google-cloud-texttospeech/src/v1beta1/text_to_speech_client.ts
index 1559f8041e8..97c577ad1a7 100644
--- a/packages/google-cloud-texttospeech/src/v1beta1/text_to_speech_client.ts
+++ b/packages/google-cloud-texttospeech/src/v1beta1/text_to_speech_client.ts
@@ -89,6 +89,13 @@ export class TextToSpeechClient {
     }
     opts.servicePath = opts.servicePath || servicePath;
     opts.port = opts.port || port;
+
+    // users can override the config from client side, like retry codes name.
+    // The detailed structure of the clientConfig can be found here: https://github.com/googleapis/gax-nodejs/blob/master/src/gax.ts#L546
+    // The way to override client config for Showcase API:
+    //
+    // const customConfig = {"interfaces": {"google.showcase.v1beta1.Echo": {"methods": {"Echo": {"retry_codes_name": "idempotent", "retry_params_name": "default"}}}}}
+    // const showcaseClient = new showcaseClient({ projectId, customConfig });
     opts.clientConfig = opts.clientConfig || {};
 
     const isBrowser = typeof window !== 'undefined';
diff --git a/packages/google-cloud-texttospeech/synth.metadata b/packages/google-cloud-texttospeech/synth.metadata
index 3ceb4e20cef..e0b66153c40 100644
--- a/packages/google-cloud-texttospeech/synth.metadata
+++ b/packages/google-cloud-texttospeech/synth.metadata
@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/nodejs-text-to-speech.git",
-        "sha": "1b36546437ec40e882d771c238a2926a5c18eee9"
+        "sha": "42502fbb2d92968dc0bc98f74066bb8849f428b0"
       }
     },
     {
@@ -19,7 +19,7 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "be74d3e532faa47eb59f1a0eaebde0860d1d8ab4"
+        "sha": "1c92077459db3dc50741e878f98b08c6261181e0"
       }
     }
   ],
diff --git a/packages/google-cloud-texttospeech/tsconfig.json b/packages/google-cloud-texttospeech/tsconfig.json
index 613d35597b5..c78f1c884ef 100644
--- a/packages/google-cloud-texttospeech/tsconfig.json
+++ b/packages/google-cloud-texttospeech/tsconfig.json
@@ -5,7 +5,7 @@
     "outDir": "build",
     "resolveJsonModule": true,
     "lib": [
-      "es2016",
+      "es2018",
       "dom"
     ]
   },