diff --git a/.github/workflows/daily.yml b/.github/workflows/daily.yml
index d328de3..89d3c88 100644
--- a/.github/workflows/daily.yml
+++ b/.github/workflows/daily.yml
@@ -12,7 +12,7 @@ jobs:
       - uses: actions/checkout@v1
       - name: install dependencies
         run: npm ci
-      - uses: oke-py/npm-audit-action@v0.1.0
+      - uses: oke-py/npm-audit-action@v1.0.0
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           issue_assignees: oke-py
diff --git a/README.md b/README.md
index c57fc06..dce5777 100644
--- a/README.md
+++ b/README.md
@@ -41,7 +41,7 @@ jobs:
       - uses: actions/checkout@v1
       - name: install dependencies
         run: npm ci
-      - uses: oke-py/npm-audit-action@v0.1.0
+      - uses: oke-py/npm-audit-action@v1.0.0
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           issue_assignees: oke-py
diff --git a/__tests__/issue.test.ts b/__tests__/issue.test.ts
index 46581d4..81530d7 100644
--- a/__tests__/issue.test.ts
+++ b/__tests__/issue.test.ts
@@ -8,8 +8,8 @@ describe('getIssueOption', () => {
     const expected: IssueOption = {
       title: 'npm audit found vulnerabilities',
       body: 'hi',
-      assignees: [''],
-      labels: ['']
+      assignees: undefined,
+      labels: undefined
     }
     expect(issue.getIssueOption('hi')).toEqual(expected)
   })
diff --git a/package-lock.json b/package-lock.json
index c6fd7ff..563bb49 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "npm-audit-action",
-  "version": "0.1.0",
+  "version": "1.0.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/package.json b/package.json
index 2e0a658..70f1421 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "npm-audit-action",
-  "version": "0.1.0",
+  "version": "1.0.0",
   "private": true,
   "description": "GitHub Action to run `npm audit`",
   "main": "lib/main.js",
diff --git a/src/issue.ts b/src/issue.ts
index 22d9da5..aafd657 100644
--- a/src/issue.ts
+++ b/src/issue.ts
@@ -2,16 +2,20 @@ import * as core from '@actions/core'
 import {IssueOption} from './interface'
 
 export function getIssueOption(body: string): IssueOption {
+  let assignees
+  let labels
+
+  if (core.getInput('issue_assignees')) {
+    assignees = core.getInput('issue_assignees').replace(/\s+/g, '').split(',')
+  }
+  if (core.getInput('issue_labels')) {
+    labels = core.getInput('issue_labels').replace(/\s+/g, '').split(',')
+  }
+
   return {
     title: core.getInput('issue_title'),
     body,
-    assignees: core
-      .getInput('issue_assignees')
-      .replace(/\s+/g, '')
-      .split(','),
-    labels: core
-      .getInput('issue_labels')
-      .replace(/\s+/g, '')
-      .split(',')
+    assignees,
+    labels
   }
 }
diff --git a/src/main.ts b/src/main.ts
index 2565fb2..7bf21b6 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -3,8 +3,8 @@ import * as github from '@actions/github'
 import stripAnsi from 'strip-ansi'
 import Octokit, {IssuesCreateResponse} from '@octokit/rest'
 import {Audit} from './audit'
-import * as issue from '../src/issue'
-import {IssueOption} from '../src/interface'
+import * as issue from './issue'
+import {IssueOption} from './interface'
 
 async function run(): Promise<void> {
   try {