diff --git a/core/constants.js b/core/constants.js
index 8bbb06981861e0d1495fadb0cf9fc6fb685ae87e..5bbc13e9d0dfefe99b3f150c615880496d10ecff 100644
--- a/core/constants.js
+++ b/core/constants.js
@@ -27,6 +27,8 @@ const Address = {
     'EXAMPLE': 'example.org',
     'HTTP': 'http:',
     'HTTPS': 'https:',
+    'RESOURCE_PATH': '/resources',
+    'ROOT_PATH': '/',
     'WWW_PREFIX': 'www.'
 };
 
diff --git a/core/file-guard.js b/core/file-guard.js
index 6f5e6966b0ec9006384044f3007b2785af065e08..fc71543aca1ee4d36442fdb7f988991712d08e05 100644
--- a/core/file-guard.js
+++ b/core/file-guard.js
@@ -39,7 +39,7 @@ fileGuard._startListening = function () {
 
 fileGuard._verifyRequest = function (requestDetails) {
 
-    let redirectUrl = chrome.runtime.getURL('/');
+    let redirectUrl = chrome.runtime.getURL(Address.ROOT_PATH);
 
     if (!requestDetails.url.endsWith(fileGuard.secret)) {
         return {redirectUrl};
@@ -50,7 +50,7 @@ fileGuard._verifyRequest = function (requestDetails) {
  * Initializations
  */
 
-fileGuard.path = chrome.runtime.getURL('/resources');
+fileGuard.path = chrome.runtime.getURL(Address.RESOURCE_PATH);
 fileGuard.secret = '';
 
 if (fileGuard.path.startsWith(Address.CHROME_EXTENSION)) {
diff --git a/core/state-manager.js b/core/state-manager.js
index 44301339b814e73e572154816ef620ed3d09d183..0620c341fbf19ddb77f86d4662d8af0842c37b8b 100644
--- a/core/state-manager.js
+++ b/core/state-manager.js
@@ -123,7 +123,7 @@ stateManager._removeTab = function (tabIdentifier) {
 
 stateManager._updateTab = function (details) {
 
-    let tabDomain, domainIsWhitelisted, tabIdentifier, frameIdentifier;
+    let tabDomain, domainIsWhitelisted, frameIdentifier, tabIdentifier;
 
     tabDomain = helpers.extractDomainFromUrl(details.url);
     domainIsWhitelisted = stateManager._domainIsWhitelisted(tabDomain);