diff --git a/package.json b/package.json
index c670e16..c07a0e0 100644
--- a/package.json
+++ b/package.json
@@ -36,7 +36,7 @@
 		"semantic-release": "^15.7.0",
 		"sinon": "^6.1.3",
 		"tempy": "^0.2.1",
-		"xo": "^0.21.0"
+		"xo": "^0.22.0"
 	},
 	"engines": {
 		"node": ">=8.3"
diff --git a/test/integration.test.js b/test/integration.test.js
index cd30d11..89895b7 100644
--- a/test/integration.test.js
+++ b/test/integration.test.js
@@ -14,7 +14,7 @@ import {
 } from './helpers/git-utils';
 
 // Save the current process.env
-const envBackup = Object.assign({}, process.env);
+const envBackup = {...process.env};
 // Save the current working diretory
 const cwd = process.cwd();
 
diff --git a/test/prepare.test.js b/test/prepare.test.js
index 77a8e76..bd33b14 100644
--- a/test/prepare.test.js
+++ b/test/prepare.test.js
@@ -5,7 +5,7 @@ import prepare from '../lib/prepare';
 import {gitRepo, gitGetCommits, gitCommitedFiles} from './helpers/git-utils';
 
 // Save the current process.env
-const envBackup = Object.assign({}, process.env);
+const envBackup = {...process.env};
 
 test.beforeEach(async t => {
 	// Delete env variables in case they are on the machine running the tests
diff --git a/test/verify.test.js b/test/verify.test.js
index dcf3c65..722ed76 100644
--- a/test/verify.test.js
+++ b/test/verify.test.js
@@ -4,7 +4,7 @@ import verify from '../lib/verify';
 import {gitRepo, gitCommits} from './helpers/git-utils';
 
 // Save the current process.env
-const envBackup = Object.assign({}, process.env);
+const envBackup = {...process.env};
 // Save the current working diretory
 const cwd = process.cwd();