diff --git a/README.md b/README.md
index 25c8049..ffc4736 100644
--- a/README.md
+++ b/README.md
@@ -17,13 +17,17 @@ This module is intended to replicate and expand upon the functionality provided
 
 ## Requirements
 
-Silverstripe 4.0 (3.1+ through previous releases)
+Silverstripe 5.0 (4.0 and 3.1+ through previous releases)
 
 ## Installation
 
 **Composer / Packagist ([best practice](http://doc.silverstripe.org/framework/en/trunk/installation/composer))**
 Add "jonom/silverstripe-betternavigator" to your requirements.
 
+```
+composer require jonom/silverstripe-betternavigator
+```
+
 **Manually**
 Download, place the folder in your project root, rename it to 'betternavigator' (if applicable) and run a dev/build?flush=1.
 
diff --git a/composer.json b/composer.json
index a5f125b..027fd78 100644
--- a/composer.json
+++ b/composer.json
@@ -16,7 +16,7 @@
         }
     ],
     "require": {
-        "silverstripe/framework": "^4.0"
+        "silverstripe/framework": "^5"
     },
     "extra": {
         "installer-name": "betternavigator",
diff --git a/src/Extension/BetterNavigatorExtension.php b/src/Extension/BetterNavigatorExtension.php
index 72acdc1..5d8d83e 100644
--- a/src/Extension/BetterNavigatorExtension.php
+++ b/src/Extension/BetterNavigatorExtension.php
@@ -2,7 +2,7 @@
 
 namespace JonoM\BetterNavigator\Extension;
 
-use SilverStripe\CMS\Controllers\SilverStripeNavigator;
+use SilverStripe\Admin\Navigator\SilverStripeNavigator;
 use SilverStripe\CMS\Model\SiteTree;
 use SilverStripe\Control\Controller;
 use SilverStripe\Control\Director;
@@ -23,6 +23,11 @@ class BetterNavigatorExtension extends DataExtension
     private static $better_navigator_edit_permission = 'CMS_ACCESS_CMSMain';
     private static $better_navigator_edit_permission_mode = 'any';
 
+    /**
+     * Extensions are singleton, so any cached results need to use a unique key
+     */
+    private $shouldDisplay = [];
+
     /**
      * @param $request
      * @param $action
@@ -161,13 +166,16 @@ private function generateNavigator()
      */
     private function shouldDisplay()
     {
-        if ($this->owner->getField('_betterNavigatorShouldDisplay') !== null) {
-            return $this->owner->getField('_betterNavigatorShouldDisplay');
+        $key = $this->owner->getUniqueKey();
+
+        if (array_key_exists($key, $this->shouldDisplay)) {
+            return $this->shouldDisplay[$key];
         }
 
         // Make sure this is a page
         if (!$this->owner->showBetterNavigator()) {
-            $this->owner->setField('_betterNavigatorShouldDisplay', false);
+            $this->shouldDisplay[$key] = false;
+
             return false;
         }
 
@@ -176,7 +184,8 @@ private function shouldDisplay()
         $canViewDraft = (Permission::check('VIEW_DRAFT_CONTENT') || Permission::check('CMS_ACCESS_CMSMain'));
 
         $result = ($isDev || $canViewDraft);
-        $this->owner->setField('_betterNavigatorShouldDisplay', $result);
+        $this->shouldDisplay[$key] = $result;
+
         return $result;
     }
 
diff --git a/templates/BetterNavigator/BetterNavigator.ss b/templates/BetterNavigator/BetterNavigator.ss
index 443eea6..2d95dca 100644
--- a/templates/BetterNavigator/BetterNavigator.ss
+++ b/templates/BetterNavigator/BetterNavigator.ss
@@ -62,14 +62,14 @@
                     <span class="bn-icon-flush"></span>
                     <%t JonoM\BetterNavigator.FLUSH_CACHE_LABEL 'Flush caches' %>
                 </a>
-                <a href="{$AbsoluteBaseURL}dev/build/?flush=1"
+                <a href="/dev/build/?flush=1"
                    target="_blank"
                    title="<%t JonoM\BetterNavigator.BUILD_DATABASE_TITLE 'Build database and flush caches (excludes template caches pre SS-3.1.7)' %>"
                 >
                     <span class="bn-icon-db"></span>
                     <%t JonoM\BetterNavigator.BUILD_DATABASE_LABEL 'Build database' %>
                 </a>
-                <a href="{$AbsoluteBaseURL}dev/" target="_blank"><span class="bn-icon-tools"></span><%t JonoM\BetterNavigator.DEV_MENU_LABEL 'Dev menu' %></a>
+                <a href="/dev/" target="_blank"><span class="bn-icon-tools"></span><%t JonoM\BetterNavigator.DEV_MENU_LABEL 'Dev menu' %></a>
 
             </div>