diff --git a/packages/google-cloud-language/smoke-test/language_service_smoke_test.js b/packages/google-cloud-language/smoke-test/language_service_smoke_test.js
index 05e15414054..8acc7ed10ff 100644
--- a/packages/google-cloud-language/smoke-test/language_service_smoke_test.js
+++ b/packages/google-cloud-language/smoke-test/language_service_smoke_test.js
@@ -18,19 +18,19 @@ describe('LanguageServiceSmokeTest', () => {
   it('successfully makes a call to the service', done => {
     const language = require('../src');
 
-    var client = new language.v1beta2.LanguageServiceClient({
+    const client = new language.v1beta2.LanguageServiceClient({
       // optional auth parameters.
     });
 
-    var content = 'Hello, world!';
-    var type = 'PLAIN_TEXT';
-    var document = {
+    const content = 'Hello, world!';
+    const type = 'PLAIN_TEXT';
+    const document = {
       content: content,
       type: type,
     };
     client.analyzeSentiment({document: document})
       .then(responses => {
-        var response = responses[0];
+        const response = responses[0];
         console.log(response);
       })
       .then(done)
diff --git a/packages/google-cloud-language/src/v1/doc/google/cloud/language/v1/doc_language_service.js b/packages/google-cloud-language/src/v1/doc/google/cloud/language/v1/doc_language_service.js
index 73083cf8650..4800b74a832 100644
--- a/packages/google-cloud-language/src/v1/doc/google/cloud/language/v1/doc_language_service.js
+++ b/packages/google-cloud-language/src/v1/doc/google/cloud/language/v1/doc_language_service.js
@@ -49,7 +49,7 @@
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.Document definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var Document = {
+const Document = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 
   /**
@@ -96,7 +96,7 @@ var Document = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.Sentence definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var Sentence = {
+const Sentence = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -145,7 +145,7 @@ var Sentence = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.Entity definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var Entity = {
+const Entity = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 
   /**
@@ -223,7 +223,7 @@ var Entity = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.Token definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var Token = {
+const Token = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -244,7 +244,7 @@ var Token = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.Sentiment definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var Sentiment = {
+const Sentiment = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -317,7 +317,7 @@ var Sentiment = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.PartOfSpeech definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var PartOfSpeech = {
+const PartOfSpeech = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 
   /**
@@ -867,7 +867,7 @@ var PartOfSpeech = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.DependencyEdge definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var DependencyEdge = {
+const DependencyEdge = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 
   /**
@@ -1321,7 +1321,7 @@ var DependencyEdge = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.EntityMention definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var EntityMention = {
+const EntityMention = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 
   /**
@@ -1363,7 +1363,7 @@ var EntityMention = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.TextSpan definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var TextSpan = {
+const TextSpan = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1381,7 +1381,7 @@ var TextSpan = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.ClassificationCategory definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var ClassificationCategory = {
+const ClassificationCategory = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1402,7 +1402,7 @@ var ClassificationCategory = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.AnalyzeSentimentRequest definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var AnalyzeSentimentRequest = {
+const AnalyzeSentimentRequest = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1428,7 +1428,7 @@ var AnalyzeSentimentRequest = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.AnalyzeSentimentResponse definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var AnalyzeSentimentResponse = {
+const AnalyzeSentimentResponse = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1449,7 +1449,7 @@ var AnalyzeSentimentResponse = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.AnalyzeEntitySentimentRequest definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var AnalyzeEntitySentimentRequest = {
+const AnalyzeEntitySentimentRequest = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1470,7 +1470,7 @@ var AnalyzeEntitySentimentRequest = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.AnalyzeEntitySentimentResponse definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var AnalyzeEntitySentimentResponse = {
+const AnalyzeEntitySentimentResponse = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1491,7 +1491,7 @@ var AnalyzeEntitySentimentResponse = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.AnalyzeEntitiesRequest definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var AnalyzeEntitiesRequest = {
+const AnalyzeEntitiesRequest = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1512,7 +1512,7 @@ var AnalyzeEntitiesRequest = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.AnalyzeEntitiesResponse definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var AnalyzeEntitiesResponse = {
+const AnalyzeEntitiesResponse = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1533,7 +1533,7 @@ var AnalyzeEntitiesResponse = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.AnalyzeSyntaxRequest definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var AnalyzeSyntaxRequest = {
+const AnalyzeSyntaxRequest = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1559,7 +1559,7 @@ var AnalyzeSyntaxRequest = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.AnalyzeSyntaxResponse definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var AnalyzeSyntaxResponse = {
+const AnalyzeSyntaxResponse = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1575,7 +1575,7 @@ var AnalyzeSyntaxResponse = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.ClassifyTextRequest definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var ClassifyTextRequest = {
+const ClassifyTextRequest = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1591,7 +1591,7 @@ var ClassifyTextRequest = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.ClassifyTextResponse definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var ClassifyTextResponse = {
+const ClassifyTextResponse = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1618,7 +1618,7 @@ var ClassifyTextResponse = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.AnnotateTextRequest definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var AnnotateTextRequest = {
+const AnnotateTextRequest = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 
   /**
@@ -1692,7 +1692,7 @@ var AnnotateTextRequest = {
  * @memberof google.cloud.language.v1
  * @see [google.cloud.language.v1.AnnotateTextResponse definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1/language_service.proto}
  */
-var AnnotateTextResponse = {
+const AnnotateTextResponse = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1706,7 +1706,7 @@ var AnnotateTextResponse = {
  * @enum {number}
  * @memberof google.cloud.language.v1
  */
-var EncodingType = {
+const EncodingType = {
 
   /**
    * If `EncodingType` is not specified, encoding-dependent information (such as
diff --git a/packages/google-cloud-language/src/v1/language_service_client.js b/packages/google-cloud-language/src/v1/language_service_client.js
index a3b010d3edb..74309f84520 100644
--- a/packages/google-cloud-language/src/v1/language_service_client.js
+++ b/packages/google-cloud-language/src/v1/language_service_client.js
@@ -72,13 +72,13 @@ class LanguageServiceClient {
     // Create a `gaxGrpc` object, with any grpc-specific options
     // sent to the client.
     opts.scopes = this.constructor.scopes;
-    var gaxGrpc = new gax.GrpcClient(opts);
+    const gaxGrpc = new gax.GrpcClient(opts);
 
     // Save the auth object to the client, for use by other methods.
     this.auth = gaxGrpc.auth;
 
     // Determine the client header string.
-    var clientHeader = [
+    const clientHeader = [
       `gl-node/${process.version}`,
       `grpc/${gaxGrpc.grpcVersion}`,
       `gax/${gax.version}`,
@@ -89,7 +89,7 @@ class LanguageServiceClient {
     }
 
     // Load the applicable protos.
-    var protos = merge(
+    const protos = merge(
       {},
       gaxGrpc.loadProto(
         path.join(__dirname, '..', '..', 'protos'),
@@ -98,7 +98,7 @@ class LanguageServiceClient {
     );
 
     // Put together the default options sent with requests.
-    var defaults = gaxGrpc.constructSettings(
+    const defaults = gaxGrpc.constructSettings(
       'google.cloud.language.v1.LanguageService',
       gapicConfig,
       opts.clientConfig,
@@ -112,14 +112,14 @@ class LanguageServiceClient {
 
     // Put together the "service stub" for
     // google.cloud.language.v1.LanguageService.
-    var languageServiceStub = gaxGrpc.createStub(
+    const languageServiceStub = gaxGrpc.createStub(
       protos.google.cloud.language.v1.LanguageService,
       opts
     );
 
     // Iterate over each of the methods that the service provides
     // and create an API call method for each.
-    var languageServiceStubMethods = [
+    const languageServiceStubMethods = [
       'analyzeSentiment',
       'analyzeEntities',
       'analyzeEntitySentiment',
@@ -132,7 +132,7 @@ class LanguageServiceClient {
         languageServiceStub.then(
           stub =>
             function() {
-              var args = Array.prototype.slice.call(arguments, 0);
+              const args = Array.prototype.slice.call(arguments, 0);
               return stub[methodName].apply(stub, args);
             }
         ),
@@ -205,14 +205,14 @@ class LanguageServiceClient {
    *
    * const language = require('@google-cloud/language');
    *
-   * var client = new language.v1.LanguageServiceClient({
+   * const client = new language.v1.LanguageServiceClient({
    *   // optional auth parameters.
    * });
    *
-   * var document = {};
+   * const document = {};
    * client.analyzeSentiment({document: document})
    *   .then(responses => {
-   *     var response = responses[0];
+   *     const response = responses[0];
    *     // doThingsWith(response)
    *   })
    *   .catch(err => {
@@ -259,14 +259,14 @@ class LanguageServiceClient {
    *
    * const language = require('@google-cloud/language');
    *
-   * var client = new language.v1.LanguageServiceClient({
+   * const client = new language.v1.LanguageServiceClient({
    *   // optional auth parameters.
    * });
    *
-   * var document = {};
+   * const document = {};
    * client.analyzeEntities({document: document})
    *   .then(responses => {
-   *     var response = responses[0];
+   *     const response = responses[0];
    *     // doThingsWith(response)
    *   })
    *   .catch(err => {
@@ -312,14 +312,14 @@ class LanguageServiceClient {
    *
    * const language = require('@google-cloud/language');
    *
-   * var client = new language.v1.LanguageServiceClient({
+   * const client = new language.v1.LanguageServiceClient({
    *   // optional auth parameters.
    * });
    *
-   * var document = {};
+   * const document = {};
    * client.analyzeEntitySentiment({document: document})
    *   .then(responses => {
-   *     var response = responses[0];
+   *     const response = responses[0];
    *     // doThingsWith(response)
    *   })
    *   .catch(err => {
@@ -370,14 +370,14 @@ class LanguageServiceClient {
    *
    * const language = require('@google-cloud/language');
    *
-   * var client = new language.v1.LanguageServiceClient({
+   * const client = new language.v1.LanguageServiceClient({
    *   // optional auth parameters.
    * });
    *
-   * var document = {};
+   * const document = {};
    * client.analyzeSyntax({document: document})
    *   .then(responses => {
-   *     var response = responses[0];
+   *     const response = responses[0];
    *     // doThingsWith(response)
    *   })
    *   .catch(err => {
@@ -418,14 +418,14 @@ class LanguageServiceClient {
    *
    * const language = require('@google-cloud/language');
    *
-   * var client = new language.v1.LanguageServiceClient({
+   * const client = new language.v1.LanguageServiceClient({
    *   // optional auth parameters.
    * });
    *
-   * var document = {};
+   * const document = {};
    * client.classifyText({document: document})
    *   .then(responses => {
-   *     var response = responses[0];
+   *     const response = responses[0];
    *     // doThingsWith(response)
    *   })
    *   .catch(err => {
@@ -475,19 +475,19 @@ class LanguageServiceClient {
    *
    * const language = require('@google-cloud/language');
    *
-   * var client = new language.v1.LanguageServiceClient({
+   * const client = new language.v1.LanguageServiceClient({
    *   // optional auth parameters.
    * });
    *
-   * var document = {};
-   * var features = {};
-   * var request = {
+   * const document = {};
+   * const features = {};
+   * const request = {
    *   document: document,
    *   features: features,
    * };
    * client.annotateText(request)
    *   .then(responses => {
-   *     var response = responses[0];
+   *     const response = responses[0];
    *     // doThingsWith(response)
    *   })
    *   .catch(err => {
diff --git a/packages/google-cloud-language/src/v1beta2/doc/google/cloud/language/v1beta2/doc_language_service.js b/packages/google-cloud-language/src/v1beta2/doc/google/cloud/language/v1beta2/doc_language_service.js
index febb701a45d..ccf06a7244d 100644
--- a/packages/google-cloud-language/src/v1beta2/doc/google/cloud/language/v1beta2/doc_language_service.js
+++ b/packages/google-cloud-language/src/v1beta2/doc/google/cloud/language/v1beta2/doc_language_service.js
@@ -49,7 +49,7 @@
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.Document definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var Document = {
+const Document = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 
   /**
@@ -96,7 +96,7 @@ var Document = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.Sentence definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var Sentence = {
+const Sentence = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -145,7 +145,7 @@ var Sentence = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.Entity definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var Entity = {
+const Entity = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 
   /**
@@ -223,7 +223,7 @@ var Entity = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.Token definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var Token = {
+const Token = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -244,7 +244,7 @@ var Token = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.Sentiment definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var Sentiment = {
+const Sentiment = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -315,7 +315,7 @@ var Sentiment = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.PartOfSpeech definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var PartOfSpeech = {
+const PartOfSpeech = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 
   /**
@@ -863,7 +863,7 @@ var PartOfSpeech = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.DependencyEdge definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var DependencyEdge = {
+const DependencyEdge = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 
   /**
@@ -1317,7 +1317,7 @@ var DependencyEdge = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.EntityMention definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var EntityMention = {
+const EntityMention = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 
   /**
@@ -1359,7 +1359,7 @@ var EntityMention = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.TextSpan definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var TextSpan = {
+const TextSpan = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1377,7 +1377,7 @@ var TextSpan = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.ClassificationCategory definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var ClassificationCategory = {
+const ClassificationCategory = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1399,7 +1399,7 @@ var ClassificationCategory = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.AnalyzeSentimentRequest definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var AnalyzeSentimentRequest = {
+const AnalyzeSentimentRequest = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1425,7 +1425,7 @@ var AnalyzeSentimentRequest = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.AnalyzeSentimentResponse definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var AnalyzeSentimentResponse = {
+const AnalyzeSentimentResponse = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1446,7 +1446,7 @@ var AnalyzeSentimentResponse = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.AnalyzeEntitySentimentRequest definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var AnalyzeEntitySentimentRequest = {
+const AnalyzeEntitySentimentRequest = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1467,7 +1467,7 @@ var AnalyzeEntitySentimentRequest = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.AnalyzeEntitySentimentResponse definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var AnalyzeEntitySentimentResponse = {
+const AnalyzeEntitySentimentResponse = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1488,7 +1488,7 @@ var AnalyzeEntitySentimentResponse = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.AnalyzeEntitiesRequest definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var AnalyzeEntitiesRequest = {
+const AnalyzeEntitiesRequest = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1509,7 +1509,7 @@ var AnalyzeEntitiesRequest = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.AnalyzeEntitiesResponse definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var AnalyzeEntitiesResponse = {
+const AnalyzeEntitiesResponse = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1530,7 +1530,7 @@ var AnalyzeEntitiesResponse = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.AnalyzeSyntaxRequest definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var AnalyzeSyntaxRequest = {
+const AnalyzeSyntaxRequest = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1556,7 +1556,7 @@ var AnalyzeSyntaxRequest = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.AnalyzeSyntaxResponse definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var AnalyzeSyntaxResponse = {
+const AnalyzeSyntaxResponse = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1572,7 +1572,7 @@ var AnalyzeSyntaxResponse = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.ClassifyTextRequest definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var ClassifyTextRequest = {
+const ClassifyTextRequest = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1588,7 +1588,7 @@ var ClassifyTextRequest = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.ClassifyTextResponse definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var ClassifyTextResponse = {
+const ClassifyTextResponse = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1615,7 +1615,7 @@ var ClassifyTextResponse = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.AnnotateTextRequest definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var AnnotateTextRequest = {
+const AnnotateTextRequest = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 
   /**
@@ -1689,7 +1689,7 @@ var AnnotateTextRequest = {
  * @memberof google.cloud.language.v1beta2
  * @see [google.cloud.language.v1beta2.AnnotateTextResponse definition in proto format]{@link https://github.com/googleapis/googleapis/blob/master/google/cloud/language/v1beta2/language_service.proto}
  */
-var AnnotateTextResponse = {
+const AnnotateTextResponse = {
   // This is for documentation. Actual contents will be loaded by gRPC.
 };
 
@@ -1703,7 +1703,7 @@ var AnnotateTextResponse = {
  * @enum {number}
  * @memberof google.cloud.language.v1beta2
  */
-var EncodingType = {
+const EncodingType = {
 
   /**
    * If `EncodingType` is not specified, encoding-dependent information (such as
diff --git a/packages/google-cloud-language/src/v1beta2/language_service_client.js b/packages/google-cloud-language/src/v1beta2/language_service_client.js
index fbefebacb28..75007fe8782 100644
--- a/packages/google-cloud-language/src/v1beta2/language_service_client.js
+++ b/packages/google-cloud-language/src/v1beta2/language_service_client.js
@@ -72,13 +72,13 @@ class LanguageServiceClient {
     // Create a `gaxGrpc` object, with any grpc-specific options
     // sent to the client.
     opts.scopes = this.constructor.scopes;
-    var gaxGrpc = new gax.GrpcClient(opts);
+    const gaxGrpc = new gax.GrpcClient(opts);
 
     // Save the auth object to the client, for use by other methods.
     this.auth = gaxGrpc.auth;
 
     // Determine the client header string.
-    var clientHeader = [
+    const clientHeader = [
       `gl-node/${process.version}`,
       `grpc/${gaxGrpc.grpcVersion}`,
       `gax/${gax.version}`,
@@ -89,7 +89,7 @@ class LanguageServiceClient {
     }
 
     // Load the applicable protos.
-    var protos = merge(
+    const protos = merge(
       {},
       gaxGrpc.loadProto(
         path.join(__dirname, '..', '..', 'protos'),
@@ -98,7 +98,7 @@ class LanguageServiceClient {
     );
 
     // Put together the default options sent with requests.
-    var defaults = gaxGrpc.constructSettings(
+    const defaults = gaxGrpc.constructSettings(
       'google.cloud.language.v1beta2.LanguageService',
       gapicConfig,
       opts.clientConfig,
@@ -112,14 +112,14 @@ class LanguageServiceClient {
 
     // Put together the "service stub" for
     // google.cloud.language.v1beta2.LanguageService.
-    var languageServiceStub = gaxGrpc.createStub(
+    const languageServiceStub = gaxGrpc.createStub(
       protos.google.cloud.language.v1beta2.LanguageService,
       opts
     );
 
     // Iterate over each of the methods that the service provides
     // and create an API call method for each.
-    var languageServiceStubMethods = [
+    const languageServiceStubMethods = [
       'analyzeSentiment',
       'analyzeEntities',
       'analyzeEntitySentiment',
@@ -132,7 +132,7 @@ class LanguageServiceClient {
         languageServiceStub.then(
           stub =>
             function() {
-              var args = Array.prototype.slice.call(arguments, 0);
+              const args = Array.prototype.slice.call(arguments, 0);
               return stub[methodName].apply(stub, args);
             }
         ),
@@ -206,14 +206,14 @@ class LanguageServiceClient {
    *
    * const language = require('@google-cloud/language');
    *
-   * var client = new language.v1beta2.LanguageServiceClient({
+   * const client = new language.v1beta2.LanguageServiceClient({
    *   // optional auth parameters.
    * });
    *
-   * var document = {};
+   * const document = {};
    * client.analyzeSentiment({document: document})
    *   .then(responses => {
-   *     var response = responses[0];
+   *     const response = responses[0];
    *     // doThingsWith(response)
    *   })
    *   .catch(err => {
@@ -260,14 +260,14 @@ class LanguageServiceClient {
    *
    * const language = require('@google-cloud/language');
    *
-   * var client = new language.v1beta2.LanguageServiceClient({
+   * const client = new language.v1beta2.LanguageServiceClient({
    *   // optional auth parameters.
    * });
    *
-   * var document = {};
+   * const document = {};
    * client.analyzeEntities({document: document})
    *   .then(responses => {
-   *     var response = responses[0];
+   *     const response = responses[0];
    *     // doThingsWith(response)
    *   })
    *   .catch(err => {
@@ -313,14 +313,14 @@ class LanguageServiceClient {
    *
    * const language = require('@google-cloud/language');
    *
-   * var client = new language.v1beta2.LanguageServiceClient({
+   * const client = new language.v1beta2.LanguageServiceClient({
    *   // optional auth parameters.
    * });
    *
-   * var document = {};
+   * const document = {};
    * client.analyzeEntitySentiment({document: document})
    *   .then(responses => {
-   *     var response = responses[0];
+   *     const response = responses[0];
    *     // doThingsWith(response)
    *   })
    *   .catch(err => {
@@ -371,14 +371,14 @@ class LanguageServiceClient {
    *
    * const language = require('@google-cloud/language');
    *
-   * var client = new language.v1beta2.LanguageServiceClient({
+   * const client = new language.v1beta2.LanguageServiceClient({
    *   // optional auth parameters.
    * });
    *
-   * var document = {};
+   * const document = {};
    * client.analyzeSyntax({document: document})
    *   .then(responses => {
-   *     var response = responses[0];
+   *     const response = responses[0];
    *     // doThingsWith(response)
    *   })
    *   .catch(err => {
@@ -419,14 +419,14 @@ class LanguageServiceClient {
    *
    * const language = require('@google-cloud/language');
    *
-   * var client = new language.v1beta2.LanguageServiceClient({
+   * const client = new language.v1beta2.LanguageServiceClient({
    *   // optional auth parameters.
    * });
    *
-   * var document = {};
+   * const document = {};
    * client.classifyText({document: document})
    *   .then(responses => {
-   *     var response = responses[0];
+   *     const response = responses[0];
    *     // doThingsWith(response)
    *   })
    *   .catch(err => {
@@ -476,19 +476,19 @@ class LanguageServiceClient {
    *
    * const language = require('@google-cloud/language');
    *
-   * var client = new language.v1beta2.LanguageServiceClient({
+   * const client = new language.v1beta2.LanguageServiceClient({
    *   // optional auth parameters.
    * });
    *
-   * var document = {};
-   * var features = {};
-   * var request = {
+   * const document = {};
+   * const features = {};
+   * const request = {
    *   document: document,
    *   features: features,
    * };
    * client.annotateText(request)
    *   .then(responses => {
-   *     var response = responses[0];
+   *     const response = responses[0];
    *     // doThingsWith(response)
    *   })
    *   .catch(err => {
diff --git a/packages/google-cloud-language/test/gapic-v1.js b/packages/google-cloud-language/test/gapic-v1.js
index 288219560c3..d68be1a6fe7 100644
--- a/packages/google-cloud-language/test/gapic-v1.js
+++ b/packages/google-cloud-language/test/gapic-v1.js
@@ -18,27 +18,27 @@ const assert = require('assert');
 
 const languageModule = require('../src');
 
-var FAKE_STATUS_CODE = 1;
-var error = new Error();
+const FAKE_STATUS_CODE = 1;
+const error = new Error();
 error.code = FAKE_STATUS_CODE;
 
 describe('LanguageServiceClient', () => {
   describe('analyzeSentiment', () => {
     it('invokes analyzeSentiment without error', done => {
-      var client = new languageModule.v1.LanguageServiceClient({
+      const client = new languageModule.v1.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
       // Mock response
-      var language = 'language-1613589672';
-      var expectedResponse = {
+      const language = 'language-1613589672';
+      const expectedResponse = {
         language: language,
       };
 
@@ -56,14 +56,14 @@ describe('LanguageServiceClient', () => {
     });
 
     it('invokes analyzeSentiment with error', done => {
-      var client = new languageModule.v1.LanguageServiceClient({
+      const client = new languageModule.v1.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
@@ -85,20 +85,20 @@ describe('LanguageServiceClient', () => {
 
   describe('analyzeEntities', () => {
     it('invokes analyzeEntities without error', done => {
-      var client = new languageModule.v1.LanguageServiceClient({
+      const client = new languageModule.v1.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
       // Mock response
-      var language = 'language-1613589672';
-      var expectedResponse = {
+      const language = 'language-1613589672';
+      const expectedResponse = {
         language: language,
       };
 
@@ -116,14 +116,14 @@ describe('LanguageServiceClient', () => {
     });
 
     it('invokes analyzeEntities with error', done => {
-      var client = new languageModule.v1.LanguageServiceClient({
+      const client = new languageModule.v1.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
@@ -145,20 +145,20 @@ describe('LanguageServiceClient', () => {
 
   describe('analyzeEntitySentiment', () => {
     it('invokes analyzeEntitySentiment without error', done => {
-      var client = new languageModule.v1.LanguageServiceClient({
+      const client = new languageModule.v1.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
       // Mock response
-      var language = 'language-1613589672';
-      var expectedResponse = {
+      const language = 'language-1613589672';
+      const expectedResponse = {
         language: language,
       };
 
@@ -176,14 +176,14 @@ describe('LanguageServiceClient', () => {
     });
 
     it('invokes analyzeEntitySentiment with error', done => {
-      var client = new languageModule.v1.LanguageServiceClient({
+      const client = new languageModule.v1.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
@@ -205,20 +205,20 @@ describe('LanguageServiceClient', () => {
 
   describe('analyzeSyntax', () => {
     it('invokes analyzeSyntax without error', done => {
-      var client = new languageModule.v1.LanguageServiceClient({
+      const client = new languageModule.v1.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
       // Mock response
-      var language = 'language-1613589672';
-      var expectedResponse = {
+      const language = 'language-1613589672';
+      const expectedResponse = {
         language: language,
       };
 
@@ -236,14 +236,14 @@ describe('LanguageServiceClient', () => {
     });
 
     it('invokes analyzeSyntax with error', done => {
-      var client = new languageModule.v1.LanguageServiceClient({
+      const client = new languageModule.v1.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
@@ -265,19 +265,19 @@ describe('LanguageServiceClient', () => {
 
   describe('classifyText', () => {
     it('invokes classifyText without error', done => {
-      var client = new languageModule.v1.LanguageServiceClient({
+      const client = new languageModule.v1.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
       // Mock response
-      var expectedResponse = {};
+      const expectedResponse = {};
 
       // Mock Grpc layer
       client._innerApiCalls.classifyText = mockSimpleGrpcMethod(
@@ -293,14 +293,14 @@ describe('LanguageServiceClient', () => {
     });
 
     it('invokes classifyText with error', done => {
-      var client = new languageModule.v1.LanguageServiceClient({
+      const client = new languageModule.v1.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
@@ -322,22 +322,22 @@ describe('LanguageServiceClient', () => {
 
   describe('annotateText', () => {
     it('invokes annotateText without error', done => {
-      var client = new languageModule.v1.LanguageServiceClient({
+      const client = new languageModule.v1.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var features = {};
-      var request = {
+      const document = {};
+      const features = {};
+      const request = {
         document: document,
         features: features,
       };
 
       // Mock response
-      var language = 'language-1613589672';
-      var expectedResponse = {
+      const language = 'language-1613589672';
+      const expectedResponse = {
         language: language,
       };
 
@@ -355,15 +355,15 @@ describe('LanguageServiceClient', () => {
     });
 
     it('invokes annotateText with error', done => {
-      var client = new languageModule.v1.LanguageServiceClient({
+      const client = new languageModule.v1.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var features = {};
-      var request = {
+      const document = {};
+      const features = {};
+      const request = {
         document: document,
         features: features,
       };
diff --git a/packages/google-cloud-language/test/gapic-v1beta2.js b/packages/google-cloud-language/test/gapic-v1beta2.js
index 5f6a9a51f19..59535945504 100644
--- a/packages/google-cloud-language/test/gapic-v1beta2.js
+++ b/packages/google-cloud-language/test/gapic-v1beta2.js
@@ -18,27 +18,27 @@ const assert = require('assert');
 
 const languageModule = require('../src');
 
-var FAKE_STATUS_CODE = 1;
-var error = new Error();
+const FAKE_STATUS_CODE = 1;
+const error = new Error();
 error.code = FAKE_STATUS_CODE;
 
 describe('LanguageServiceClient', () => {
   describe('analyzeSentiment', () => {
     it('invokes analyzeSentiment without error', done => {
-      var client = new languageModule.v1beta2.LanguageServiceClient({
+      const client = new languageModule.v1beta2.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
       // Mock response
-      var language = 'language-1613589672';
-      var expectedResponse = {
+      const language = 'language-1613589672';
+      const expectedResponse = {
         language: language,
       };
 
@@ -56,14 +56,14 @@ describe('LanguageServiceClient', () => {
     });
 
     it('invokes analyzeSentiment with error', done => {
-      var client = new languageModule.v1beta2.LanguageServiceClient({
+      const client = new languageModule.v1beta2.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
@@ -85,20 +85,20 @@ describe('LanguageServiceClient', () => {
 
   describe('analyzeEntities', () => {
     it('invokes analyzeEntities without error', done => {
-      var client = new languageModule.v1beta2.LanguageServiceClient({
+      const client = new languageModule.v1beta2.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
       // Mock response
-      var language = 'language-1613589672';
-      var expectedResponse = {
+      const language = 'language-1613589672';
+      const expectedResponse = {
         language: language,
       };
 
@@ -116,14 +116,14 @@ describe('LanguageServiceClient', () => {
     });
 
     it('invokes analyzeEntities with error', done => {
-      var client = new languageModule.v1beta2.LanguageServiceClient({
+      const client = new languageModule.v1beta2.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
@@ -145,20 +145,20 @@ describe('LanguageServiceClient', () => {
 
   describe('analyzeEntitySentiment', () => {
     it('invokes analyzeEntitySentiment without error', done => {
-      var client = new languageModule.v1beta2.LanguageServiceClient({
+      const client = new languageModule.v1beta2.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
       // Mock response
-      var language = 'language-1613589672';
-      var expectedResponse = {
+      const language = 'language-1613589672';
+      const expectedResponse = {
         language: language,
       };
 
@@ -176,14 +176,14 @@ describe('LanguageServiceClient', () => {
     });
 
     it('invokes analyzeEntitySentiment with error', done => {
-      var client = new languageModule.v1beta2.LanguageServiceClient({
+      const client = new languageModule.v1beta2.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
@@ -205,20 +205,20 @@ describe('LanguageServiceClient', () => {
 
   describe('analyzeSyntax', () => {
     it('invokes analyzeSyntax without error', done => {
-      var client = new languageModule.v1beta2.LanguageServiceClient({
+      const client = new languageModule.v1beta2.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
       // Mock response
-      var language = 'language-1613589672';
-      var expectedResponse = {
+      const language = 'language-1613589672';
+      const expectedResponse = {
         language: language,
       };
 
@@ -236,14 +236,14 @@ describe('LanguageServiceClient', () => {
     });
 
     it('invokes analyzeSyntax with error', done => {
-      var client = new languageModule.v1beta2.LanguageServiceClient({
+      const client = new languageModule.v1beta2.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
@@ -265,19 +265,19 @@ describe('LanguageServiceClient', () => {
 
   describe('classifyText', () => {
     it('invokes classifyText without error', done => {
-      var client = new languageModule.v1beta2.LanguageServiceClient({
+      const client = new languageModule.v1beta2.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
       // Mock response
-      var expectedResponse = {};
+      const expectedResponse = {};
 
       // Mock Grpc layer
       client._innerApiCalls.classifyText = mockSimpleGrpcMethod(
@@ -293,14 +293,14 @@ describe('LanguageServiceClient', () => {
     });
 
     it('invokes classifyText with error', done => {
-      var client = new languageModule.v1beta2.LanguageServiceClient({
+      const client = new languageModule.v1beta2.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var request = {
+      const document = {};
+      const request = {
         document: document,
       };
 
@@ -322,22 +322,22 @@ describe('LanguageServiceClient', () => {
 
   describe('annotateText', () => {
     it('invokes annotateText without error', done => {
-      var client = new languageModule.v1beta2.LanguageServiceClient({
+      const client = new languageModule.v1beta2.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var features = {};
-      var request = {
+      const document = {};
+      const features = {};
+      const request = {
         document: document,
         features: features,
       };
 
       // Mock response
-      var language = 'language-1613589672';
-      var expectedResponse = {
+      const language = 'language-1613589672';
+      const expectedResponse = {
         language: language,
       };
 
@@ -355,15 +355,15 @@ describe('LanguageServiceClient', () => {
     });
 
     it('invokes annotateText with error', done => {
-      var client = new languageModule.v1beta2.LanguageServiceClient({
+      const client = new languageModule.v1beta2.LanguageServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
 
       // Mock request
-      var document = {};
-      var features = {};
-      var request = {
+      const document = {};
+      const features = {};
+      const request = {
         document: document,
         features: features,
       };