diff --git a/code/Controllers/LeftAndMainPageIconsExtension.php b/code/Controllers/LeftAndMainPageIconsExtension.php
index e962322f06..ed0e7e69fd 100644
--- a/code/Controllers/LeftAndMainPageIconsExtension.php
+++ b/code/Controllers/LeftAndMainPageIconsExtension.php
@@ -26,7 +26,7 @@ class LeftAndMainPageIconsExtension extends Extension implements Flushable
      * @throws InvalidArgumentException
      * @throws ReflectionException
      */
-    public function init()
+    protected function onInit()
     {
         Requirements::customCSS($this->generatePageIconsCss(), CMSMain::PAGE_ICONS_ID);
     }
diff --git a/code/Model/SiteTree.php b/code/Model/SiteTree.php
index 1ab304dfe5..348365e9c1 100755
--- a/code/Model/SiteTree.php
+++ b/code/Model/SiteTree.php
@@ -1494,7 +1494,7 @@ public function MetaComponents()
             ];
         }
 
-        $this->extend('MetaComponents', $tags);
+        $this->extend('updateMetaComponents', $tags);
 
         return $tags;
     }
@@ -1598,7 +1598,7 @@ public function MetaTags($includeTitle = true)
             $tagString .= $this->obj('ExtraMeta')->forTemplate();
         }
 
-        $this->extend('MetaTags', $tagString);
+        $this->extend('updateMetaTags', $tagString);
 
         return $tagString;
     }
diff --git a/code/Model/SiteTreeExtension.php b/code/Model/SiteTreeExtension.php
index e2cce8ed0d..f3260e77b0 100644
--- a/code/Model/SiteTreeExtension.php
+++ b/code/Model/SiteTreeExtension.php
@@ -70,7 +70,7 @@ protected function onAfterUnpublish()
      * logged in user
      * @return boolean|null Return false to deny rights, or null to yield to default
      */
-    public function canAddChildren($member)
+    protected function canAddChildren($member)
     {
     }
 
@@ -83,7 +83,7 @@ public function canAddChildren($member)
      * logged in user
      * @return boolean|null Return false to deny rights, or null to yield to default
      */
-    public function canPublish($member)
+    protected function canPublish($member)
     {
     }
 
@@ -100,7 +100,7 @@ public function canPublish($member)
      * (Legacy support) If this is true, then do not reduce the 'home' urlsegment
      * to an empty link
      */
-    public function updateRelativeLink(&$link, $base, $action)
+    protected function updateRelativeLink(&$link, $base, $action)
     {
     }
 }
diff --git a/tests/php/Model/SiteTreeTest_AdminDeniedExtension.php b/tests/php/Model/SiteTreeTest_AdminDeniedExtension.php
index b2ff7d90b9..b73f19a251 100644
--- a/tests/php/Model/SiteTreeTest_AdminDeniedExtension.php
+++ b/tests/php/Model/SiteTreeTest_AdminDeniedExtension.php
@@ -10,27 +10,27 @@
  */
 class SiteTreeTest_AdminDeniedExtension extends DataExtension implements TestOnly
 {
-    public function canCreate($member)
+    protected function canCreate($member)
     {
         return false;
     }
 
-    public function canEdit($member)
+    protected function canEdit($member)
     {
         return false;
     }
 
-    public function canDelete($member)
+    protected function canDelete($member)
     {
         return false;
     }
 
-    public function canAddChildren()
+    protected function canAddChildren()
     {
         return false;
     }
 
-    public function canView()
+    protected function canView()
     {
         return false;
     }
diff --git a/tests/php/Model/SiteTreeTest_ExtensionA.php b/tests/php/Model/SiteTreeTest_ExtensionA.php
index 9d3cd427aa..0e9e0baae6 100644
--- a/tests/php/Model/SiteTreeTest_ExtensionA.php
+++ b/tests/php/Model/SiteTreeTest_ExtensionA.php
@@ -10,12 +10,12 @@ class SiteTreeTest_ExtensionA extends SiteTreeExtension implements TestOnly
 {
     public static $can_publish = true;
 
-    public function canPublish($member)
+    protected function canPublish($member)
     {
         return static::$can_publish;
     }
 
-    public function updateLink(&$link, $action = null)
+    protected function updateLink(&$link, $action = null)
     {
         $link = Controller::join_links($link, '?extra=1');
     }
diff --git a/tests/php/Model/SiteTreeTest_ExtensionB.php b/tests/php/Model/SiteTreeTest_ExtensionB.php
index cf42dbbc30..be93b57195 100644
--- a/tests/php/Model/SiteTreeTest_ExtensionB.php
+++ b/tests/php/Model/SiteTreeTest_ExtensionB.php
@@ -10,12 +10,12 @@ class SiteTreeTest_ExtensionB extends SiteTreeExtension implements TestOnly
 {
     public static $can_publish = true;
 
-    public function canPublish($member)
+    protected function canPublish($member)
     {
         return static::$can_publish;
     }
 
-    public function updateLink(&$link, $action = null)
+    protected function updateLink(&$link, $action = null)
     {
         $link = Controller::join_links('http://www.updatedhost.com', $link);
     }