diff --git a/src/serviceWorker.js b/src/serviceWorker.js
index b04b771..91aa453 100644
--- a/src/serviceWorker.js
+++ b/src/serviceWorker.js
@@ -60,7 +60,7 @@ function registerValidSW(swUrl, config) {
     .then(registration => {
       registration.onupdatefound = () => {
         const installingWorker = registration.installing;
-        if (installingWorker == null) {
+        if (installingWorker === null) {
           return;
         }
         installingWorker.onstatechange = () => {
@@ -108,7 +108,7 @@ function checkValidServiceWorker(swUrl, config) {
       const contentType = response.headers.get('content-type');
       if (
         response.status === 404 ||
-        (contentType != null && contentType.indexOf('javascript') === -1)
+        (contentType !== null && contentType.indexOf('javascript') === -1)
       ) {
         // No service worker found. Probably a different app. Reload the page.
         navigator.serviceWorker.ready.then(registration => {