diff --git a/packages/google-cloud-oslogin/protos/protos.js b/packages/google-cloud-oslogin/protos/protos.js
index a3b6551c41a..289b865a126 100644
--- a/packages/google-cloud-oslogin/protos/protos.js
+++ b/packages/google-cloud-oslogin/protos/protos.js
@@ -28,7 +28,7 @@
     var $Reader = $protobuf.Reader, $Writer = $protobuf.Writer, $util = $protobuf.util;
     
     // Exported root namespace
-    var $root = $protobuf.roots._google_cloud_os_login_3_0_0_protos || ($protobuf.roots._google_cloud_os_login_3_0_0_protos = {});
+    var $root = $protobuf.roots._google_cloud_os_login_protos || ($protobuf.roots._google_cloud_os_login_protos = {});
     
     $root.google = (function() {
     
diff --git a/packages/google-cloud-oslogin/src/v1/os_login_service_client.ts b/packages/google-cloud-oslogin/src/v1/os_login_service_client.ts
index 5786a3af281..f8810df656b 100644
--- a/packages/google-cloud-oslogin/src/v1/os_login_service_client.ts
+++ b/packages/google-cloud-oslogin/src/v1/os_login_service_client.ts
@@ -93,6 +93,13 @@ export class OsLoginServiceClient {
     }
     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-oslogin/src/v1beta/os_login_service_client.ts b/packages/google-cloud-oslogin/src/v1beta/os_login_service_client.ts
index b9d7beec170..1bebe887cea 100644
--- a/packages/google-cloud-oslogin/src/v1beta/os_login_service_client.ts
+++ b/packages/google-cloud-oslogin/src/v1beta/os_login_service_client.ts
@@ -93,6 +93,13 @@ export class OsLoginServiceClient {
     }
     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-oslogin/synth.metadata b/packages/google-cloud-oslogin/synth.metadata
index 2419f876566..9ed6791b108 100644
--- a/packages/google-cloud-oslogin/synth.metadata
+++ b/packages/google-cloud-oslogin/synth.metadata
@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/nodejs-os-login.git",
-        "sha": "dd4328ea06e8320f029953039118e05cb9242a50"
+        "sha": "9313894fbae15b9693155145ac708886f0676fe8"
       }
     },
     {
@@ -19,7 +19,7 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "be74d3e532faa47eb59f1a0eaebde0860d1d8ab4"
+        "sha": "1c92077459db3dc50741e878f98b08c6261181e0"
       }
     }
   ],
diff --git a/packages/google-cloud-oslogin/tsconfig.json b/packages/google-cloud-oslogin/tsconfig.json
index 613d35597b5..c78f1c884ef 100644
--- a/packages/google-cloud-oslogin/tsconfig.json
+++ b/packages/google-cloud-oslogin/tsconfig.json
@@ -5,7 +5,7 @@
     "outDir": "build",
     "resolveJsonModule": true,
     "lib": [
-      "es2016",
+      "es2018",
       "dom"
     ]
   },