diff --git a/mozilla/browser/base/content/browser.js b/mozilla/browser/base/content/browser.js
index 3947b93e3cb..755af0a019e 100644
--- a/mozilla/browser/base/content/browser.js
+++ b/mozilla/browser/base/content/browser.js
@@ -242,6 +242,18 @@ const gSessionHistoryObserver = {
     backCommand.setAttribute("disabled", "true");
     var fwdCommand = document.getElementById("Browser:Forward");
     fwdCommand.setAttribute("disabled", "true");
+
+    //Clear undo history of all URL Bars
+    var windowManager = Components.classes['@mozilla.org/appshell/window-mediator;1'].getService();
+    var windowManagerInterface = windowManager.QueryInterface(Components.interfaces.nsIWindowMediator);
+    var windows = windowManagerInterface.getEnumerator("navigator:browser");
+    while (windows.hasMoreElements()) {
+      var urlBar = windows.getNext().gURLBar;
+      if (urlBar) {
+        urlBar.editor.enableUndo(false);
+        urlBar.editor.enableUndo(true);
+      }
+    }
   }
 };
 
diff --git a/mozilla/browser/base/content/sanitize.js b/mozilla/browser/base/content/sanitize.js
index 99af9a3e68f..31026c11423 100644
--- a/mozilla/browser/base/content/sanitize.js
+++ b/mozilla/browser/base/content/sanitize.js
@@ -151,6 +151,19 @@ Sanitizer.prototype = {
     formdata: {
       clear: function ()
       {
+        //Clear undo history of all searchBars
+        var windowManager = Components.classes['@mozilla.org/appshell/window-mediator;1'].getService();
+        var windowManagerInterface = windowManager.QueryInterface(Components.interfaces.nsIWindowMediator);
+        var windows = windowManagerInterface.getEnumerator("navigator:browser");
+        while (windows.hasMoreElements()) {
+          var searchBar = windows.getNext().document.getElementById("searchbar");
+          if (searchBar) {
+            searchBar.mTextbox.value = "";
+            searchBar.mTextbox.editor.enableUndo(false);
+            searchBar.mTextbox.editor.enableUndo(true);
+          }
+        }
+
         var formHistory = Components.classes["@mozilla.org/satchel/form-history;1"]
                                     .getService(Components.interfaces.nsIFormHistory);
         formHistory.removeAllEntries();
diff --git a/mozilla/browser/base/content/search.xml b/mozilla/browser/base/content/search.xml
index 2c9cecf2843..fa67c8ae836 100644
--- a/mozilla/browser/base/content/search.xml
+++ b/mozilla/browser/base/content/search.xml
@@ -389,9 +389,13 @@
 
         doCommand: function (aCommand)
         {
+          // Clear the searchbar and its undo history
+          this.mOuter.value = "";
+          this.mOuter.editor.enableUndo(false);
+          this.mOuter.editor.enableUndo(true);
+
           this.mOuter.formHistSvc.removeEntriesForName(
               this.mOuter.getAttribute("autocompletesearchparam"));
-          this.mOuter.value = "";
         }
       })
       ]]></field>