diff --git a/__tests__/audit.test.ts b/__tests__/audit.test.ts
index e1e5b05..2bf4654 100644
--- a/__tests__/audit.test.ts
+++ b/__tests__/audit.test.ts
@@ -55,7 +55,7 @@ describe('run', () => {
     expect(audit.foundVulnerability()).toBeFalsy()
   })
 
-  test('throws an error if error is not null', async () => {
+  test('throws an error if error is not null', () => {
     mocked(child_process).spawnSync.mockImplementation((): any => {
       return {
         pid: 100,
@@ -69,12 +69,11 @@ describe('run', () => {
     })
 
     expect.assertions(1)
-    const r = audit.run('low')
     const e = new Error('Something is wrong')
-    await expect(r).rejects.toEqual(e)
+    expect(() => audit.run('low')).toThrowError(e)
   })
 
-  test('throws an error if status is null', async () => {
+  test('throws an error if status is null', () => {
     mocked(child_process).spawnSync.mockImplementation((): any => {
       return {
         pid: 100,
@@ -88,12 +87,11 @@ describe('run', () => {
     })
 
     expect.assertions(1)
-    const r = audit.run('low')
     const e = new Error('the subprocess terminated due to a signal.')
-    await expect(r).rejects.toEqual(e)
+    expect(() => audit.run('low')).toThrowError(e)
   })
 
-  test('throws an error if stderr is null', async () => {
+  test('throws an error if stderr is null', () => {
     mocked(child_process).spawnSync.mockImplementation((): any => {
       return {
         pid: 100,
@@ -107,8 +105,7 @@ describe('run', () => {
     })
 
     expect.assertions(1)
-    const r = audit.run('low')
     const e = new Error('Something is wrong')
-    await expect(r).rejects.toEqual(e)
+    expect(() => audit.run('low')).toThrowError(e)
   })
 })
diff --git a/dist/index.js b/dist/index.js
index ddd8f7c..c13c30d 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -1107,15 +1107,6 @@ module.exports = windowsRelease;
 
 "use strict";
 
-var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
-    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
-    return new (P || (P = Promise))(function (resolve, reject) {
-        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
-        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
-        step((generator = generator.apply(thisArg, _arguments || [])).next());
-    });
-};
 var __importDefault = (this && this.__importDefault) || function (mod) {
     return (mod && mod.__esModule) ? mod : { "default": mod };
 };
@@ -1123,33 +1114,33 @@ Object.defineProperty(exports, "__esModule", { value: true });
 exports.Audit = void 0;
 const child_process_1 = __webpack_require__(129);
 const strip_ansi_1 = __importDefault(__webpack_require__(90));
+const SPAWN_PROCESS_BUFFER_SIZE = 10485760; // 10MiB
 class Audit {
     constructor() {
         this.stdout = '';
         this.status = null;
     }
     run(auditLevel) {
-        return __awaiter(this, void 0, void 0, function* () {
-            try {
-                const result = child_process_1.spawnSync('npm', ['audit', '--audit-level', auditLevel], {
-                    encoding: 'utf-8'
-                });
-                if (result.error) {
-                    throw result.error;
-                }
-                if (result.status === null) {
-                    throw new Error('the subprocess terminated due to a signal.');
-                }
-                if (result.stderr && result.stderr.length > 0) {
-                    throw new Error(result.stderr);
-                }
-                this.status = result.status;
-                this.stdout = result.stdout;
+        try {
+            const result = child_process_1.spawnSync('npm', ['audit', '--audit-level', auditLevel], {
+                encoding: 'utf-8',
+                maxBuffer: SPAWN_PROCESS_BUFFER_SIZE
+            });
+            if (result.error) {
+                throw result.error;
             }
-            catch (error) {
-                throw error;
+            if (result.status === null) {
+                throw new Error('the subprocess terminated due to a signal.');
             }
-        });
+            if (result.stderr && result.stderr.length > 0) {
+                throw new Error(result.stderr);
+            }
+            this.status = result.status;
+            this.stdout = result.stdout;
+        }
+        catch (error) {
+            throw error;
+        }
     }
     foundVulnerability() {
         // `npm audit` return 1 when it found vulnerabilities
@@ -30401,7 +30392,7 @@ exports.requestLog = requestLog;
 /***/ 919:
 /***/ (function(module) {
 
-module.exports = {"_from":"@octokit/rest@^16.43.1","_id":"@octokit/rest@16.43.1","_inBundle":false,"_integrity":"sha512-gfFKwRT/wFxq5qlNjnW2dh+qh74XgTQ2B179UX5K1HYCluioWj8Ndbgqw2PVqa1NnVJkGHp2ovMpVn/DImlmkw==","_location":"/@actions/github/@octokit/rest","_phantomChildren":{},"_requested":{"type":"range","registry":true,"raw":"@octokit/rest@^16.43.1","name":"@octokit/rest","escapedName":"@octokit%2frest","scope":"@octokit","rawSpec":"^16.43.1","saveSpec":null,"fetchSpec":"^16.43.1"},"_requiredBy":["/@actions/github"],"_resolved":"https://registry.npmjs.org/@octokit/rest/-/rest-16.43.1.tgz","_shasum":"3b11e7d1b1ac2bbeeb23b08a17df0b20947eda6b","_spec":"@octokit/rest@^16.43.1","_where":"/Users/naoki/go/src/github.com/oke-py/npm-audit-action/node_modules/@actions/github","author":{"name":"Gregor Martynus","url":"https://github.com/gr2m"},"bugs":{"url":"https://github.com/octokit/rest.js/issues"},"bundleDependencies":false,"bundlesize":[{"path":"./dist/octokit-rest.min.js.gz","maxSize":"33 kB"}],"contributors":[{"name":"Mike de Boer","email":"info@mikedeboer.nl"},{"name":"Fabian Jakobs","email":"fabian@c9.io"},{"name":"Joe Gallo","email":"joe@brassafrax.com"},{"name":"Gregor Martynus","url":"https://github.com/gr2m"}],"dependencies":{"@octokit/auth-token":"^2.4.0","@octokit/plugin-paginate-rest":"^1.1.1","@octokit/plugin-request-log":"^1.0.0","@octokit/plugin-rest-endpoint-methods":"2.4.0","@octokit/request":"^5.2.0","@octokit/request-error":"^1.0.2","atob-lite":"^2.0.0","before-after-hook":"^2.0.0","btoa-lite":"^1.0.0","deprecation":"^2.0.0","lodash.get":"^4.4.2","lodash.set":"^4.3.2","lodash.uniq":"^4.5.0","octokit-pagination-methods":"^1.1.0","once":"^1.4.0","universal-user-agent":"^4.0.0"},"deprecated":false,"description":"GitHub REST API client for Node.js","devDependencies":{"@gimenete/type-writer":"^0.1.3","@octokit/auth":"^1.1.1","@octokit/fixtures-server":"^5.0.6","@octokit/graphql":"^4.2.0","@types/node":"^13.1.0","bundlesize":"^0.18.0","chai":"^4.1.2","compression-webpack-plugin":"^3.1.0","cypress":"^3.0.0","glob":"^7.1.2","http-proxy-agent":"^4.0.0","lodash.camelcase":"^4.3.0","lodash.merge":"^4.6.1","lodash.upperfirst":"^4.3.1","lolex":"^5.1.2","mkdirp":"^1.0.0","mocha":"^7.0.1","mustache":"^4.0.0","nock":"^11.3.3","npm-run-all":"^4.1.2","nyc":"^15.0.0","prettier":"^1.14.2","proxy":"^1.0.0","semantic-release":"^17.0.0","sinon":"^8.0.0","sinon-chai":"^3.0.0","sort-keys":"^4.0.0","string-to-arraybuffer":"^1.0.0","string-to-jsdoc-comment":"^1.0.0","typescript":"^3.3.1","webpack":"^4.0.0","webpack-bundle-analyzer":"^3.0.0","webpack-cli":"^3.0.0"},"files":["index.js","index.d.ts","lib","plugins"],"homepage":"https://github.com/octokit/rest.js#readme","keywords":["octokit","github","rest","api-client"],"license":"MIT","name":"@octokit/rest","nyc":{"ignore":["test"]},"publishConfig":{"access":"public"},"release":{"publish":["@semantic-release/npm",{"path":"@semantic-release/github","assets":["dist/*","!dist/*.map.gz"]}]},"repository":{"type":"git","url":"git+https://github.com/octokit/rest.js.git"},"scripts":{"build":"npm-run-all build:*","build:browser":"npm-run-all build:browser:*","build:browser:development":"webpack --mode development --entry . --output-library=Octokit --output=./dist/octokit-rest.js --profile --json > dist/bundle-stats.json","build:browser:production":"webpack --mode production --entry . --plugin=compression-webpack-plugin --output-library=Octokit --output-path=./dist --output-filename=octokit-rest.min.js --devtool source-map","build:ts":"npm run -s update-endpoints:typescript","coverage":"nyc report --reporter=html && open coverage/index.html","generate-bundle-report":"webpack-bundle-analyzer dist/bundle-stats.json --mode=static --no-open --report dist/bundle-report.html","lint":"prettier --check '{lib,plugins,scripts,test}/**/*.{js,json,ts}' 'docs/*.{js,json}' 'docs/src/**/*' index.js README.md package.json","lint:fix":"prettier --write '{lib,plugins,scripts,test}/**/*.{js,json,ts}' 'docs/*.{js,json}' 'docs/src/**/*' index.js README.md package.json","postvalidate:ts":"tsc --noEmit --target es6 test/typescript-validate.ts","prebuild:browser":"mkdirp dist/","pretest":"npm run -s lint","prevalidate:ts":"npm run -s build:ts","start-fixtures-server":"octokit-fixtures-server","test":"nyc mocha test/mocha-node-setup.js \"test/*/**/*-test.js\"","test:browser":"cypress run --browser chrome","update-endpoints":"npm-run-all update-endpoints:*","update-endpoints:fetch-json":"node scripts/update-endpoints/fetch-json","update-endpoints:typescript":"node scripts/update-endpoints/typescript","validate:ts":"tsc --target es6 --noImplicitAny index.d.ts"},"types":"index.d.ts","version":"16.43.1"};
+module.exports = {"name":"@octokit/rest","version":"16.43.1","publishConfig":{"access":"public"},"description":"GitHub REST API client for Node.js","keywords":["octokit","github","rest","api-client"],"author":"Gregor Martynus (https://github.com/gr2m)","contributors":[{"name":"Mike de Boer","email":"info@mikedeboer.nl"},{"name":"Fabian Jakobs","email":"fabian@c9.io"},{"name":"Joe Gallo","email":"joe@brassafrax.com"},{"name":"Gregor Martynus","url":"https://github.com/gr2m"}],"repository":"https://github.com/octokit/rest.js","dependencies":{"@octokit/auth-token":"^2.4.0","@octokit/plugin-paginate-rest":"^1.1.1","@octokit/plugin-request-log":"^1.0.0","@octokit/plugin-rest-endpoint-methods":"2.4.0","@octokit/request":"^5.2.0","@octokit/request-error":"^1.0.2","atob-lite":"^2.0.0","before-after-hook":"^2.0.0","btoa-lite":"^1.0.0","deprecation":"^2.0.0","lodash.get":"^4.4.2","lodash.set":"^4.3.2","lodash.uniq":"^4.5.0","octokit-pagination-methods":"^1.1.0","once":"^1.4.0","universal-user-agent":"^4.0.0"},"devDependencies":{"@gimenete/type-writer":"^0.1.3","@octokit/auth":"^1.1.1","@octokit/fixtures-server":"^5.0.6","@octokit/graphql":"^4.2.0","@types/node":"^13.1.0","bundlesize":"^0.18.0","chai":"^4.1.2","compression-webpack-plugin":"^3.1.0","cypress":"^3.0.0","glob":"^7.1.2","http-proxy-agent":"^4.0.0","lodash.camelcase":"^4.3.0","lodash.merge":"^4.6.1","lodash.upperfirst":"^4.3.1","lolex":"^5.1.2","mkdirp":"^1.0.0","mocha":"^7.0.1","mustache":"^4.0.0","nock":"^11.3.3","npm-run-all":"^4.1.2","nyc":"^15.0.0","prettier":"^1.14.2","proxy":"^1.0.0","semantic-release":"^17.0.0","sinon":"^8.0.0","sinon-chai":"^3.0.0","sort-keys":"^4.0.0","string-to-arraybuffer":"^1.0.0","string-to-jsdoc-comment":"^1.0.0","typescript":"^3.3.1","webpack":"^4.0.0","webpack-bundle-analyzer":"^3.0.0","webpack-cli":"^3.0.0"},"types":"index.d.ts","scripts":{"coverage":"nyc report --reporter=html && open coverage/index.html","lint":"prettier --check '{lib,plugins,scripts,test}/**/*.{js,json,ts}' 'docs/*.{js,json}' 'docs/src/**/*' index.js README.md package.json","lint:fix":"prettier --write '{lib,plugins,scripts,test}/**/*.{js,json,ts}' 'docs/*.{js,json}' 'docs/src/**/*' index.js README.md package.json","pretest":"npm run -s lint","test":"nyc mocha test/mocha-node-setup.js \"test/*/**/*-test.js\"","test:browser":"cypress run --browser chrome","build":"npm-run-all build:*","build:ts":"npm run -s update-endpoints:typescript","prebuild:browser":"mkdirp dist/","build:browser":"npm-run-all build:browser:*","build:browser:development":"webpack --mode development --entry . --output-library=Octokit --output=./dist/octokit-rest.js --profile --json > dist/bundle-stats.json","build:browser:production":"webpack --mode production --entry . --plugin=compression-webpack-plugin --output-library=Octokit --output-path=./dist --output-filename=octokit-rest.min.js --devtool source-map","generate-bundle-report":"webpack-bundle-analyzer dist/bundle-stats.json --mode=static --no-open --report dist/bundle-report.html","update-endpoints":"npm-run-all update-endpoints:*","update-endpoints:fetch-json":"node scripts/update-endpoints/fetch-json","update-endpoints:typescript":"node scripts/update-endpoints/typescript","prevalidate:ts":"npm run -s build:ts","validate:ts":"tsc --target es6 --noImplicitAny index.d.ts","postvalidate:ts":"tsc --noEmit --target es6 test/typescript-validate.ts","start-fixtures-server":"octokit-fixtures-server"},"license":"MIT","files":["index.js","index.d.ts","lib","plugins"],"nyc":{"ignore":["test"]},"release":{"publish":["@semantic-release/npm",{"path":"@semantic-release/github","assets":["dist/*","!dist/*.map.gz"]}]},"bundlesize":[{"path":"./dist/octokit-rest.min.js.gz","maxSize":"33 kB"}],"_resolved":"https://registry.npmjs.org/@octokit/rest/-/rest-16.43.1.tgz","_integrity":"sha512-gfFKwRT/wFxq5qlNjnW2dh+qh74XgTQ2B179UX5K1HYCluioWj8Ndbgqw2PVqa1NnVJkGHp2ovMpVn/DImlmkw==","_from":"@octokit/rest@16.43.1"};
 
 /***/ }),
 
diff --git a/src/audit.ts b/src/audit.ts
index 5a61a58..bd05b0d 100644
--- a/src/audit.ts
+++ b/src/audit.ts
@@ -1,17 +1,20 @@
 import {spawnSync, SpawnSyncReturns} from 'child_process'
 import stripAnsi from 'strip-ansi'
 
+const SPAWN_PROCESS_BUFFER_SIZE = 10485760 // 10MiB
+
 export class Audit {
   stdout = ''
   private status: number | null = null
 
-  public async run(auditLevel: string): Promise<void> {
+  public run(auditLevel: string): void {
     try {
       const result: SpawnSyncReturns<string> = spawnSync(
         'npm',
         ['audit', '--audit-level', auditLevel],
         {
-          encoding: 'utf-8'
+          encoding: 'utf-8',
+          maxBuffer: SPAWN_PROCESS_BUFFER_SIZE
         }
       )