diff --git a/core/state-manager.js b/core/state-manager.js
index a21bba118979665dc9eb2d316a314c87414e9916..13a3297e352affc576392b4ee5fc12b650082074 100644
--- a/core/state-manager.js
+++ b/core/state-manager.js
@@ -324,7 +324,7 @@ chrome.tabs.onRemoved.addListener(stateManager._removeTab);
 
 chrome.webRequest.onBeforeRequest.addListener(function (requestDetails) {
 
-    if (requestDetails.tabId !== -1) {
+    if (requestDetails.tabId !== -1 && stateManager.tabs[requestDetails.tabId]) {
 
         stateManager.tabs[requestDetails.tabId].details = {
             'url': requestDetails.url
diff --git a/modules/internal/helpers.js b/modules/internal/helpers.js
index 8628be05be3760753028129b646002df808f3cc7..e8226a9283525ee7de12d304fc917297da2467b1 100644
--- a/modules/internal/helpers.js
+++ b/modules/internal/helpers.js
@@ -88,7 +88,7 @@ helpers.normalizeDomain = function (domain) {
     return domain;
 };
 
-helpers.extractDomainFromUrl = function (url, normalize) {
+helpers.extractDomainFromUrl = function (url = '', normalize) {
 
     let extractedDomain;