diff --git a/core/constants.js b/core/constants.js
index 6731979430798529f61f2a87626ca05d07576d1a..f5e2f71b05d0b3a08fd3fd169f4bb2063c4dc0a4 100644
--- a/core/constants.js
+++ b/core/constants.js
@@ -64,6 +64,7 @@ const WebRequest = {
 };
 
 const WebRequestType = {
+    'MAIN_FRAME': 'main_frame',
     'XHR': 'xmlhttprequest'
 };
 
diff --git a/core/state-manager.js b/core/state-manager.js
index dc543ca60d39f179f0c950621a1264c706211f74..31a021f6348ea1ab049a8a14c9195bad112d7e49 100644
--- a/core/state-manager.js
+++ b/core/state-manager.js
@@ -105,7 +105,6 @@ stateManager._createTab = function (tab) {
     };
 
     requestFilters = {
-
         'tabId': tabIdentifier,
         'urls': stateManager.validHosts
     };
@@ -226,7 +225,7 @@ chrome.webRequest.onBeforeRequest.addListener(function (requestDetails) {
         };
     }
 
-}, {'types': ['main_frame'], 'urls': [Address.ANY]});
+}, {'types': [WebRequestType.MAIN_FRAME], 'urls': [Address.ANY]});
 
 chrome.webNavigation.onCommitted.addListener(stateManager._updateTab, {
     'url': [{'urlContains': ':'}]