diff --git a/packages/grpc-health-check/gulpfile.ts b/packages/grpc-health-check/gulpfile.ts
index 9f436dfd..28e21dc6 100644
--- a/packages/grpc-health-check/gulpfile.ts
+++ b/packages/grpc-health-check/gulpfile.ts
@@ -26,25 +26,17 @@ const healthCheckDir = __dirname;
 const baseDir = path.resolve(healthCheckDir, '..', '..');
 const testDir = path.resolve(healthCheckDir, 'test');
 
-const cleanLinks = () => {
-  return del(path.resolve(healthCheckDir, 'node_modules/grpc'));
-}
+const cleanLinks = () => del(path.resolve(healthCheckDir, 'node_modules/grpc'));
 
 const cleanAll = gulp.parallel(cleanLinks);
 
-const runInstall = () => {
-  return execa('npm', ['install', '--unsafe-perm'], {cwd: healthCheckDir, stdio: 'inherit'});
-};
+const runInstall = () => execa('npm', ['install', '--unsafe-perm'], {cwd: healthCheckDir, stdio: 'inherit'});
 
 const install = gulp.series(cleanLinks, runInstall);
 
-const linkAdd = () => {
-  linkSync(healthCheckDir, './node_modules/grpc', '../grpc-native-core');
-};
+const linkAdd = () => linkSync(healthCheckDir, './node_modules/grpc', '../grpc-native-core');
 
-const test = () => {
-  return gulp.src(`${testDir}/*.js`).pipe(mocha({reporter: 'mocha-jenkins-reporter'}));
-};
+const test = () => gulp.src(`${testDir}/*.js`).pipe(mocha({reporter: 'mocha-jenkins-reporter'}));
 
 export {
   cleanLinks,
diff --git a/packages/grpc-js/gulpfile.ts b/packages/grpc-js/gulpfile.ts
index f0626405..817b2a36 100644
--- a/packages/grpc-js/gulpfile.ts
+++ b/packages/grpc-js/gulpfile.ts
@@ -40,20 +40,14 @@ const execNpmVerb = (verb: string, ...args: string[]) =>
   execa('npm', [verb, ...args], {cwd: jsCoreDir, stdio: 'inherit'});
 const execNpmCommand = execNpmVerb.bind(null, 'run');
 
-const install = () => {
-  execNpmVerb('install', '--unsafe-perm');
-};
+const install = () => execNpmVerb('install', '--unsafe-perm');
 
 /**
  * Runs tslint on files in src/, with linting rules defined in tslint.json.
  */
-const lint = () => {
-  execNpmCommand('check');
-};
+const lint = () => execNpmCommand('check');
 
-const clean = () => {
-  execNpmCommand('clean');
-};
+const clean = () => execNpmCommand('clean');
 
 const cleanAll = gulp.parallel(clean);
 
@@ -61,13 +55,9 @@ const cleanAll = gulp.parallel(clean);
  * Transpiles TypeScript files in src/ to JavaScript according to the settings
  * found in tsconfig.json.
  */
-const compile = () => {
-  execNpmCommand('compile');
-}
+const compile = () => execNpmCommand('compile');
 
-const copyTestFixtures = () => {
-  return ncpP(`${jsCoreDir}/test/fixtures`, `${outDir}/test/fixtures`);
-}
+const copyTestFixtures = () => ncpP(`${jsCoreDir}/test/fixtures`, `${outDir}/test/fixtures`);
 
 const runTests = () => {
   if (semver.satisfies(process.version, '^8.11.2 || >=9.4')) {
diff --git a/packages/grpc-native-core/gulpfile.ts b/packages/grpc-native-core/gulpfile.ts
index 4828981c..cfb601d0 100644
--- a/packages/grpc-native-core/gulpfile.ts
+++ b/packages/grpc-native-core/gulpfile.ts
@@ -30,10 +30,8 @@ const testDir = path.resolve(nativeCoreDir, 'test');
 const pkg = require('./package');
 const jshintConfig = pkg.jshintConfig;
 
-const clean = () => {
-  return del([path.resolve(nativeCoreDir, 'build'),
-	            path.resolve(nativeCoreDir, 'ext/node')]);
-};
+const clean = () => del([path.resolve(nativeCoreDir, 'build'),
+	                       path.resolve(nativeCoreDir, 'ext/node')]);
 
 const cleanAll = gulp.parallel(clean);
 
@@ -69,8 +67,8 @@ const test = gulp.series(build, runTests);
 
 const docGen = (cb) => {
   var config = require('./jsdoc_conf.json');
-  gulp.src([`${nativeCoreDir}/README.md`, `${nativeCoreDir}/index.js`, `${srcDir}/*.js`], {read: false})
-      .pipe(jsdoc(config, cb));
+  return gulp.src([`${nativeCoreDir}/README.md`, `${nativeCoreDir}/index.js`, `${srcDir}/*.js`], {read: false})
+             .pipe(jsdoc(config, cb));
 };
 
 export {
diff --git a/packages/proto-loader/gulpfile.ts b/packages/proto-loader/gulpfile.ts
index 21bb7fde..04fd131b 100644
--- a/packages/proto-loader/gulpfile.ts
+++ b/packages/proto-loader/gulpfile.ts
@@ -36,22 +36,14 @@ const execNpmVerb = (verb: string, ...args: string[]) =>
   execa('npm', [verb, ...args], {cwd: protojsDir, stdio: 'inherit'});
 const execNpmCommand = execNpmVerb.bind(null, 'run');
 
-const install = () => {
-  execNpmVerb('install', '--unsafe-perm');
-};
+const install = () => execNpmVerb('install', '--unsafe-perm');
 
 /**
  * Runs tslint on files in src/, with linting rules defined in tslint.json.
  */
-const lint = () => {
-  execNpmCommand('check');
-};
+const lint = () => execNpmCommand('check');
 
-const cleanFiles = () => {
-  execNpmCommand('clean');
-};
-
-const clean = gulp.series(install, cleanFiles);
+const clean = () => execNpmCommand('clean');
 
 const cleanAll = gulp.parallel(clean);
 
@@ -59,9 +51,7 @@ const cleanAll = gulp.parallel(clean);
  * Transpiles TypeScript files in src/ and test/ to JavaScript according to the settings
  * found in tsconfig.json.
  */
-const compile = () => {
-  execNpmCommand('compile');
-};
+const compile = () => execNpmCommand('compile');
 
 /**
  * Transpiles src/ and test/, and then runs all tests.
diff --git a/test/gulpfile.ts b/test/gulpfile.ts
index 73843354..3fde9d9e 100644
--- a/test/gulpfile.ts
+++ b/test/gulpfile.ts
@@ -30,7 +30,7 @@ const install = () => {
   return execa('npm', ['install'], {cwd: testDir, stdio: 'inherit'});
 };
 
-const cleanAll = () => {};
+const cleanAll = () => Promise.resolve();
 
 const test = () => {
   // run mocha tests matching a glob with a pre-required fixture,