diff --git a/templates/typescript_gapic/package.json.njk b/templates/typescript_gapic/package.json.njk
index bb6f6480e..7d952b8b7 100644
--- a/templates/typescript_gapic/package.json.njk
+++ b/templates/typescript_gapic/package.json.njk
@@ -27,7 +27,7 @@ limitations under the License.
     "build/protos"
   ],
   "dependencies": {
-    "google-gax": "^1.9.0"
+    "google-gax": "^1.10.0"
   },
   "devDependencies": {
     "@types/mocha": "^5.2.5",
diff --git a/templates/typescript_gapic/src/$version/$service_client.ts.njk b/templates/typescript_gapic/src/$version/$service_client.ts.njk
index 9baac44a6..3c0970883 100644
--- a/templates/typescript_gapic/src/$version/$service_client.ts.njk
+++ b/templates/typescript_gapic/src/$version/$service_client.ts.njk
@@ -21,9 +21,9 @@ limitations under the License.
 
 import * as gax from 'google-gax';
 {% if service.longRunning.length > 0 -%}
-import {Callback, LROperation, Descriptors, ClientOptions} from 'google-gax';
+import {APICallback, Callback, CallOptions, LROperation, Descriptors, ClientOptions} from 'google-gax';
 {%- else -%}
-import {Callback, Descriptors, ClientOptions} from 'google-gax';
+import {APICallback, Callback, CallOptions, Descriptors, ClientOptions} from 'google-gax';
 {%- endif %}
 import * as path from 'path';
 {% if (service.paging.length > 0) %}
@@ -56,10 +56,12 @@ export interface PaginationResponse<
  */
 export class {{ service.name }}Client {
   private _descriptors: Descriptors = {page: {}, stream: {}, longrunning: {}};
+  private _{{ service.name.toCamelCase() }}Stub: Promise<{[name: string]: Function}>;
   private _innerApiCalls: {[name: string]: Function};
   {%- if (service.pathTemplates.length > 0) %}
   private _pathTemplates: {[name: string]: gax.PathTemplate};
   {%- endif %}
+  private _terminated = false;
   auth: gax.GoogleAuth;
 
   /**
@@ -235,7 +237,7 @@ export class {{ service.name }}Client {
 
     // Put together the "service stub" for
     // {{api.naming.protoPackage}}.{{ service.name }}.
-    const {{ service.name.toCamelCase() }}Stub = gaxGrpc.createStub(
+    this._{{ service.name.toCamelCase() }}Stub = gaxGrpc.createStub(
         opts.fallback ?
           (protos as protobuf.Root).lookupService('{{api.naming.protoPackage}}.{{ service.name }}') :
           // tslint:disable-next-line no-any
@@ -254,21 +256,32 @@ export class {{ service.name }}Client {
     ];
 
     for (const methodName of {{ service.name.toCamelCase() }}StubMethods) {
-      const innerCallPromise = {{ service.name.toCamelCase() }}Stub.then(
-        (stub: {[method: string]: Function}) => (...args: Array<{}>) => {
+      const innerCallPromise = this._{{ service.name.toCamelCase() }}Stub.then(
+        stub => (...args: Array<{}>) => {
           return stub[methodName].apply(stub, args);
         },
         (err: Error|null|undefined) => () => {
           throw err;
         });
 
-      this._innerApiCalls[methodName] = gaxModule.createApiCall(
+      const apiCall = gaxModule.createApiCall(
         innerCallPromise,
         defaults[methodName],
         this._descriptors.page[methodName] ||
-            this._descriptors.stream[methodName] || 
+            this._descriptors.stream[methodName] ||
             this._descriptors.longrunning[methodName]
       );
+
+      this._innerApiCalls[methodName] = (
+        argument: {},
+        callOptions?: CallOptions,
+        callback?: APICallback
+      ) => {
+         if (this._terminated) {
+            return Promise.reject('The client has already been closed.');
+         }
+         return apiCall(argument, callOptions, callback);
+      };
     }
   }
 
@@ -589,4 +602,19 @@ export class {{ service.name }}Client {
 {%- endfor %}  
 {%- endfor %}
 {%- endif %}
+
+  /**
+   * Terminate the GRPC channel and close the client.
+   *
+   * The client will no longer be usable and all future behavior is undefined.
+   */
+  close(): Promise<void> {
+    if (!this._terminated) {
+      return this._{{ service.name.toCamelCase() }}Stub.then(stub => {
+        this._terminated = true;
+        stub.close();
+      });
+    }
+    return Promise.resolve();
+  }
 }
diff --git a/typescript/test/testdata/keymanager/package.json.baseline b/typescript/test/testdata/keymanager/package.json.baseline
index 6efdd7e3f..b3f5d46c7 100644
--- a/typescript/test/testdata/keymanager/package.json.baseline
+++ b/typescript/test/testdata/keymanager/package.json.baseline
@@ -10,7 +10,7 @@
     "build/protos"
   ],
   "dependencies": {
-    "google-gax": "^1.9.0"
+    "google-gax": "^1.10.0"
   },
   "devDependencies": {
     "@types/mocha": "^5.2.5",
diff --git a/typescript/test/testdata/keymanager/src/v1/key_management_service_client.ts.baseline b/typescript/test/testdata/keymanager/src/v1/key_management_service_client.ts.baseline
index 539313daa..a46ba0816 100644
--- a/typescript/test/testdata/keymanager/src/v1/key_management_service_client.ts.baseline
+++ b/typescript/test/testdata/keymanager/src/v1/key_management_service_client.ts.baseline
@@ -17,7 +17,7 @@
 // ** All changes to this file may be overwritten. **
 
 import * as gax from 'google-gax';
-import {Callback, Descriptors, ClientOptions} from 'google-gax';
+import {APICallback, Callback, CallOptions, Descriptors, ClientOptions} from 'google-gax';
 import * as path from 'path';
 
 import { Transform } from 'stream';
@@ -58,7 +58,9 @@ export interface PaginationResponse<
  */
 export class KeyManagementServiceClient {
   private _descriptors: Descriptors = {page: {}, stream: {}, longrunning: {}};
+  private _keyManagementServiceStub: Promise<{[name: string]: Function}>;
   private _innerApiCalls: {[name: string]: Function};
+  private _terminated = false;
   auth: gax.GoogleAuth;
 
   /**
@@ -175,7 +177,7 @@ export class KeyManagementServiceClient {
 
     // Put together the "service stub" for
     // google.cloud.kms.v1.KeyManagementService.
-    const keyManagementServiceStub = gaxGrpc.createStub(
+    this._keyManagementServiceStub = gaxGrpc.createStub(
         opts.fallback ?
           (protos as protobuf.Root).lookupService('google.cloud.kms.v1.KeyManagementService') :
           // tslint:disable-next-line no-any
@@ -188,21 +190,32 @@ export class KeyManagementServiceClient {
         ['listKeyRings', 'listCryptoKeys', 'listCryptoKeyVersions', 'listImportJobs', 'getKeyRing', 'getCryptoKey', 'getCryptoKeyVersion', 'getPublicKey', 'getImportJob', 'createKeyRing', 'createCryptoKey', 'createCryptoKeyVersion', 'importCryptoKeyVersion', 'createImportJob', 'updateCryptoKey', 'updateCryptoKeyVersion', 'encrypt', 'decrypt', 'asymmetricSign', 'asymmetricDecrypt', 'updateCryptoKeyPrimaryVersion', 'destroyCryptoKeyVersion', 'restoreCryptoKeyVersion'];
 
     for (const methodName of keyManagementServiceStubMethods) {
-      const innerCallPromise = keyManagementServiceStub.then(
-        (stub: {[method: string]: Function}) => (...args: Array<{}>) => {
+      const innerCallPromise = this._keyManagementServiceStub.then(
+        stub => (...args: Array<{}>) => {
           return stub[methodName].apply(stub, args);
         },
         (err: Error|null|undefined) => () => {
           throw err;
         });
 
-      this._innerApiCalls[methodName] = gaxModule.createApiCall(
+      const apiCall = gaxModule.createApiCall(
         innerCallPromise,
         defaults[methodName],
         this._descriptors.page[methodName] ||
-            this._descriptors.stream[methodName] || 
+            this._descriptors.stream[methodName] ||
             this._descriptors.longrunning[methodName]
       );
+
+      this._innerApiCalls[methodName] = (
+        argument: {},
+        callOptions?: CallOptions,
+        callback?: APICallback
+      ) => {
+         if (this._terminated) {
+            return Promise.reject('The client has already been closed.');
+         }
+         return apiCall(argument, callOptions, callback);
+      };
     }
   }
 
@@ -2068,4 +2081,19 @@ export class KeyManagementServiceClient {
       callSettings
     );
   }
+
+  /**
+   * Terminate the GRPC channel and close the client.
+   *
+   * The client will no longer be usable and all future behavior is undefined.
+   */
+  close(): Promise<void> {
+    if (!this._terminated) {
+      return this._keyManagementServiceStub.then(stub => {
+        this._terminated = true;
+        stub.close();
+      });
+    }
+    return Promise.resolve();
+  }
 }
diff --git a/typescript/test/testdata/showcase/package.json.baseline b/typescript/test/testdata/showcase/package.json.baseline
index 5d690961e..dbacca51d 100644
--- a/typescript/test/testdata/showcase/package.json.baseline
+++ b/typescript/test/testdata/showcase/package.json.baseline
@@ -10,7 +10,7 @@
     "build/protos"
   ],
   "dependencies": {
-    "google-gax": "^1.9.0"
+    "google-gax": "^1.10.0"
   },
   "devDependencies": {
     "@types/mocha": "^5.2.5",
diff --git a/typescript/test/testdata/showcase/src/v1beta1/echo_client.ts.baseline b/typescript/test/testdata/showcase/src/v1beta1/echo_client.ts.baseline
index 433aa2c1b..ad2c52090 100644
--- a/typescript/test/testdata/showcase/src/v1beta1/echo_client.ts.baseline
+++ b/typescript/test/testdata/showcase/src/v1beta1/echo_client.ts.baseline
@@ -17,7 +17,7 @@
 // ** All changes to this file may be overwritten. **
 
 import * as gax from 'google-gax';
-import {Callback, LROperation, Descriptors, ClientOptions} from 'google-gax';
+import {APICallback, Callback, CallOptions, LROperation, Descriptors, ClientOptions} from 'google-gax';
 import * as path from 'path';
 
 import { Transform } from 'stream';
@@ -51,7 +51,9 @@ export interface PaginationResponse<
  */
 export class EchoClient {
   private _descriptors: Descriptors = {page: {}, stream: {}, longrunning: {}};
+  private _echoStub: Promise<{[name: string]: Function}>;
   private _innerApiCalls: {[name: string]: Function};
+  private _terminated = false;
   auth: gax.GoogleAuth;
 
   /**
@@ -193,7 +195,7 @@ export class EchoClient {
 
     // Put together the "service stub" for
     // google.showcase.v1beta1.Echo.
-    const echoStub = gaxGrpc.createStub(
+    this._echoStub = gaxGrpc.createStub(
         opts.fallback ?
           (protos as protobuf.Root).lookupService('google.showcase.v1beta1.Echo') :
           // tslint:disable-next-line no-any
@@ -206,21 +208,32 @@ export class EchoClient {
         ['echo', 'expand', 'collect', 'chat', 'pagedExpand', 'wait'];
 
     for (const methodName of echoStubMethods) {
-      const innerCallPromise = echoStub.then(
-        (stub: {[method: string]: Function}) => (...args: Array<{}>) => {
+      const innerCallPromise = this._echoStub.then(
+        stub => (...args: Array<{}>) => {
           return stub[methodName].apply(stub, args);
         },
         (err: Error|null|undefined) => () => {
           throw err;
         });
 
-      this._innerApiCalls[methodName] = gaxModule.createApiCall(
+      const apiCall = gaxModule.createApiCall(
         innerCallPromise,
         defaults[methodName],
         this._descriptors.page[methodName] ||
-            this._descriptors.stream[methodName] || 
+            this._descriptors.stream[methodName] ||
             this._descriptors.longrunning[methodName]
       );
+
+      this._innerApiCalls[methodName] = (
+        argument: {},
+        callOptions?: CallOptions,
+        callback?: APICallback
+      ) => {
+         if (this._terminated) {
+            return Promise.reject('The client has already been closed.');
+         }
+         return apiCall(argument, callOptions, callback);
+      };
     }
   }
 
@@ -580,4 +593,19 @@ export class EchoClient {
       callSettings
     );
   }
+
+  /**
+   * Terminate the GRPC channel and close the client.
+   *
+   * The client will no longer be usable and all future behavior is undefined.
+   */
+  close(): Promise<void> {
+    if (!this._terminated) {
+      return this._echoStub.then(stub => {
+        this._terminated = true;
+        stub.close();
+      });
+    }
+    return Promise.resolve();
+  }
 }
diff --git a/typescript/test/testdata/texttospeech/package.json.baseline b/typescript/test/testdata/texttospeech/package.json.baseline
index 84e222e36..9a39365f2 100644
--- a/typescript/test/testdata/texttospeech/package.json.baseline
+++ b/typescript/test/testdata/texttospeech/package.json.baseline
@@ -10,7 +10,7 @@
     "build/protos"
   ],
   "dependencies": {
-    "google-gax": "^1.9.0"
+    "google-gax": "^1.10.0"
   },
   "devDependencies": {
     "@types/mocha": "^5.2.5",
diff --git a/typescript/test/testdata/texttospeech/src/v1/text_to_speech_client.ts.baseline b/typescript/test/testdata/texttospeech/src/v1/text_to_speech_client.ts.baseline
index c6e40e355..79951755a 100644
--- a/typescript/test/testdata/texttospeech/src/v1/text_to_speech_client.ts.baseline
+++ b/typescript/test/testdata/texttospeech/src/v1/text_to_speech_client.ts.baseline
@@ -17,7 +17,7 @@
 // ** All changes to this file may be overwritten. **
 
 import * as gax from 'google-gax';
-import {Callback, Descriptors, ClientOptions} from 'google-gax';
+import {APICallback, Callback, CallOptions, Descriptors, ClientOptions} from 'google-gax';
 import * as path from 'path';
 
 import * as protosTypes from '../../protos/protos';
@@ -34,7 +34,9 @@ const version = require('../../../package.json').version;
  */
 export class TextToSpeechClient {
   private _descriptors: Descriptors = {page: {}, stream: {}, longrunning: {}};
+  private _textToSpeechStub: Promise<{[name: string]: Function}>;
   private _innerApiCalls: {[name: string]: Function};
+  private _terminated = false;
   auth: gax.GoogleAuth;
 
   /**
@@ -137,7 +139,7 @@ export class TextToSpeechClient {
 
     // Put together the "service stub" for
     // google.cloud.texttospeech.v1.TextToSpeech.
-    const textToSpeechStub = gaxGrpc.createStub(
+    this._textToSpeechStub = gaxGrpc.createStub(
         opts.fallback ?
           (protos as protobuf.Root).lookupService('google.cloud.texttospeech.v1.TextToSpeech') :
           // tslint:disable-next-line no-any
@@ -150,21 +152,32 @@ export class TextToSpeechClient {
         ['listVoices', 'synthesizeSpeech'];
 
     for (const methodName of textToSpeechStubMethods) {
-      const innerCallPromise = textToSpeechStub.then(
-        (stub: {[method: string]: Function}) => (...args: Array<{}>) => {
+      const innerCallPromise = this._textToSpeechStub.then(
+        stub => (...args: Array<{}>) => {
           return stub[methodName].apply(stub, args);
         },
         (err: Error|null|undefined) => () => {
           throw err;
         });
 
-      this._innerApiCalls[methodName] = gaxModule.createApiCall(
+      const apiCall = gaxModule.createApiCall(
         innerCallPromise,
         defaults[methodName],
         this._descriptors.page[methodName] ||
-            this._descriptors.stream[methodName] || 
+            this._descriptors.stream[methodName] ||
             this._descriptors.longrunning[methodName]
       );
+
+      this._innerApiCalls[methodName] = (
+        argument: {},
+        callOptions?: CallOptions,
+        callback?: APICallback
+      ) => {
+         if (this._terminated) {
+            return Promise.reject('The client has already been closed.');
+         }
+         return apiCall(argument, callOptions, callback);
+      };
     }
   }
 
@@ -336,4 +349,19 @@ export class TextToSpeechClient {
     return this._innerApiCalls.synthesizeSpeech(request, options, callback);
   }
 
+
+  /**
+   * Terminate the GRPC channel and close the client.
+   *
+   * The client will no longer be usable and all future behavior is undefined.
+   */
+  close(): Promise<void> {
+    if (!this._terminated) {
+      return this._textToSpeechStub.then(stub => {
+        this._terminated = true;
+        stub.close();
+      });
+    }
+    return Promise.resolve();
+  }
 }
diff --git a/typescript/test/testdata/translate/package.json.baseline b/typescript/test/testdata/translate/package.json.baseline
index c34b51122..a94a226c7 100644
--- a/typescript/test/testdata/translate/package.json.baseline
+++ b/typescript/test/testdata/translate/package.json.baseline
@@ -10,7 +10,7 @@
     "build/protos"
   ],
   "dependencies": {
-    "google-gax": "^1.9.0"
+    "google-gax": "^1.10.0"
   },
   "devDependencies": {
     "@types/mocha": "^5.2.5",
diff --git a/typescript/test/testdata/translate/src/v3beta1/translation_service_client.ts.baseline b/typescript/test/testdata/translate/src/v3beta1/translation_service_client.ts.baseline
index 6d156b552..781e9a5d4 100644
--- a/typescript/test/testdata/translate/src/v3beta1/translation_service_client.ts.baseline
+++ b/typescript/test/testdata/translate/src/v3beta1/translation_service_client.ts.baseline
@@ -17,7 +17,7 @@
 // ** All changes to this file may be overwritten. **
 
 import * as gax from 'google-gax';
-import {Callback, LROperation, Descriptors, ClientOptions} from 'google-gax';
+import {APICallback, Callback, CallOptions, LROperation, Descriptors, ClientOptions} from 'google-gax';
 import * as path from 'path';
 
 import { Transform } from 'stream';
@@ -48,8 +48,10 @@ export interface PaginationResponse<
  */
 export class TranslationServiceClient {
   private _descriptors: Descriptors = {page: {}, stream: {}, longrunning: {}};
+  private _translationServiceStub: Promise<{[name: string]: Function}>;
   private _innerApiCalls: {[name: string]: Function};
   private _pathTemplates: {[name: string]: gax.PathTemplate};
+  private _terminated = false;
   auth: gax.GoogleAuth;
 
   /**
@@ -211,7 +213,7 @@ export class TranslationServiceClient {
 
     // Put together the "service stub" for
     // google.cloud.translation.v3beta1.TranslationService.
-    const translationServiceStub = gaxGrpc.createStub(
+    this._translationServiceStub = gaxGrpc.createStub(
         opts.fallback ?
           (protos as protobuf.Root).lookupService('google.cloud.translation.v3beta1.TranslationService') :
           // tslint:disable-next-line no-any
@@ -224,21 +226,32 @@ export class TranslationServiceClient {
         ['translateText', 'detectLanguage', 'getSupportedLanguages', 'batchTranslateText', 'createGlossary', 'listGlossaries', 'getGlossary', 'deleteGlossary'];
 
     for (const methodName of translationServiceStubMethods) {
-      const innerCallPromise = translationServiceStub.then(
-        (stub: {[method: string]: Function}) => (...args: Array<{}>) => {
+      const innerCallPromise = this._translationServiceStub.then(
+        stub => (...args: Array<{}>) => {
           return stub[methodName].apply(stub, args);
         },
         (err: Error|null|undefined) => () => {
           throw err;
         });
 
-      this._innerApiCalls[methodName] = gaxModule.createApiCall(
+      const apiCall = gaxModule.createApiCall(
         innerCallPromise,
         defaults[methodName],
         this._descriptors.page[methodName] ||
-            this._descriptors.stream[methodName] || 
+            this._descriptors.stream[methodName] ||
             this._descriptors.longrunning[methodName]
       );
+
+      this._innerApiCalls[methodName] = (
+        argument: {},
+        callOptions?: CallOptions,
+        callback?: APICallback
+      ) => {
+         if (this._terminated) {
+            return Promise.reject('The client has already been closed.');
+         }
+         return apiCall(argument, callOptions, callback);
+      };
     }
   }
 
@@ -1055,4 +1068,19 @@ export class TranslationServiceClient {
   matchGlossaryFromGlossaryName(glossaryName: string){
     return this._pathTemplates.glossaryPathTemplate.match(glossaryName).glossary;
   }
+
+  /**
+   * Terminate the GRPC channel and close the client.
+   *
+   * The client will no longer be usable and all future behavior is undefined.
+   */
+  close(): Promise<void> {
+    if (!this._terminated) {
+      return this._translationServiceStub.then(stub => {
+        this._terminated = true;
+        stub.close();
+      });
+    }
+    return Promise.resolve();
+  }
 }
diff --git a/typescript/test/util.ts b/typescript/test/util.ts
index c111c3b0a..b7b85d204 100644
--- a/typescript/test/util.ts
+++ b/typescript/test/util.ts
@@ -82,6 +82,27 @@ function checkIdenticalFile(
   const readOutput = fs.readFileSync(outputFullPath).toString();
   const baselineOutput = fs.readFileSync(baselineFullPath).toString();
   if (readOutput === baselineOutput) return IDENTICAL_FILE;
+
+  const readOutputLines = readOutput.split('\n');
+  const baselineOutputLines = baselineOutput.split('\n');
+
+  if (readOutputLines.length !== baselineOutputLines.length) {
+    console.warn(
+      `Line count for ${outputFullPath} was ${readOutputLines.length}, ` +
+        `but expected ${baselineOutputLines.length}.`
+    );
+  } else {
+    for (let i = 0; i < readOutputLines.length; ++i) {
+      if (readOutputLines[i] !== baselineOutputLines[i]) {
+        console.warn(
+          `Line ${i + 1} of ${outputFullPath} was \n\t"${
+            readOutputLines[i]
+          }"\nbut expected\n\t"${baselineOutputLines[i]}"`
+        );
+      }
+    }
+  }
+
   return FILE_WITH_DIFF_CONTENT;
 }