diff --git a/app/code/core/Mage/Core/Controller/Varien/Router/Admin.php b/app/code/core/Mage/Core/Controller/Varien/Router/Admin.php
index b5651fe07db..bf76d93692a 100644
--- a/app/code/core/Mage/Core/Controller/Varien/Router/Admin.php
+++ b/app/code/core/Mage/Core/Controller/Varien/Router/Admin.php
@@ -129,13 +129,10 @@ public function collectRoutes($configArea, $useRouterName)
      */
     public function addModule($frontName, $moduleName, $routeName)
     {
-        $isExtensionsCompatibilityMode = (bool)(string)Mage::getConfig()->getNode(
-            'default/admin/security/extensions_compatibility_mode'
-        );
         $configRouterFrontName = (string)Mage::getConfig()->getNode(
             Mage_Adminhtml_Helper_Data::XML_PATH_ADMINHTML_ROUTER_FRONTNAME
         );
-        if ($isExtensionsCompatibilityMode || ($frontName == $configRouterFrontName)) {
+        if ($frontName == $configRouterFrontName) {
             return parent::addModule($frontName, $moduleName, $routeName);
         } else {
             return $this;
diff --git a/app/code/core/Mage/Core/etc/config.xml b/app/code/core/Mage/Core/etc/config.xml
index d7ce041219d..7863ab46a7b 100644
--- a/app/code/core/Mage/Core/etc/config.xml
+++ b/app/code/core/Mage/Core/etc/config.xml
@@ -436,7 +436,6 @@
                 <use_form_key>1</use_form_key>
                 <domain_policy_backend>2</domain_policy_backend>
                 <domain_policy_frontend>2</domain_policy_frontend>
-                <extensions_compatibility_mode>1</extensions_compatibility_mode>
                 <session_cookie_lifetime>10800</session_cookie_lifetime>
                 <secure_system_configuration_save_disabled>0</secure_system_configuration_save_disabled>
             </security>
diff --git a/app/code/core/Mage/Core/etc/system.xml b/app/code/core/Mage/Core/etc/system.xml
index 489b1e6fcf2..d31f05d7847 100644
--- a/app/code/core/Mage/Core/etc/system.xml
+++ b/app/code/core/Mage/Core/etc/system.xml
@@ -1246,16 +1246,6 @@
                             <show_in_website>0</show_in_website>
                             <show_in_store>0</show_in_store>
                         </domain_policy_frontend>
-                        <extensions_compatibility_mode translate="label comment">
-                            <label>Admin routing compatibility mode for extensions</label>
-                            <comment>Enabling this setting increases risk of automated attacks against admin functionality.</comment>
-                            <frontend_type>select</frontend_type>
-                            <sort_order>6</sort_order>
-                            <source_model>adminhtml/system_config_source_enabledisable</source_model>
-                            <show_in_default>1</show_in_default>
-                            <show_in_website>0</show_in_website>
-                            <show_in_store>0</show_in_store>
-                        </extensions_compatibility_mode>
                         <crate_admin_user_notification translate="label comment">
                             <label>New Admin User Create Notification</label>
                             <comment>This setting enable notification when new admin user created.</comment>
diff --git a/app/locale/en_US/Mage_Core.csv b/app/locale/en_US/Mage_Core.csv
index 5c4528c8d69..bdf720668cc 100644
--- a/app/locale/en_US/Mage_Core.csv
+++ b/app/locale/en_US/Mage_Core.csv
@@ -12,7 +12,6 @@
 "Admin","Admin"
 "Admin Base URL","Admin Base URL"
 "Admin User Emails","Admin User Emails"
-"Admin routing compatibility mode for extensions","Admin routing compatibility mode for extensions"
 "Advanced","Advanced"
 "Advanced Cache Settings","Advanced Cache Settings"
 "After selecting a new media storage location, press the Synchronize button
@@ -133,7 +132,6 @@
 "Enabled for Admin","Enabled for Admin"
 "Enabled for Frontend","Enabled for Frontend"
 "Enabling ability to run Magento in a frame is not recommended for security reasons.","Enabling ability to run Magento in a frame is not recommended for security reasons."
-"Enabling this setting increases risk of automated attacks against admin functionality.","Enabling this setting increases risk of automated attacks against admin functionality."
 "Environment Update Time","Environment Update Time"
 "Error in file: ""%s"" - %s","Error in file: ""%s"" - %s"
 "European Union Countries","European Union Countries"