diff --git a/index.js b/index.js
index 786bf07..fef1545 100644
--- a/index.js
+++ b/index.js
@@ -1,4 +1,4 @@
-"use strict";
+'use strict';
 
 module.exports = function isNegativeZero(value) {
 	var number = Number(value);
diff --git a/test.js b/test.js
index 3511fd8..da2e262 100644
--- a/test.js
+++ b/test.js
@@ -1,4 +1,4 @@
-"use strict";
+'use strict';
 
 var test = require('tape');
 var isNegativeZero = require('./');