diff --git a/code/controllers/ContentController.php b/code/controllers/ContentController.php
index d5ca5e96..4f0c7bff 100644
--- a/code/controllers/ContentController.php
+++ b/code/controllers/ContentController.php
@@ -398,6 +398,7 @@ HTML;
 	 * templates directly in the template.
 	 */
 	function LangAttributes() {
+		Deprecation::notice('2.5', 'Use ContentLocale() instead and write attribute names suitable to XHTML/HTML instead.');
 		$locale = $this->ContentLocale();
 		return "xml:lang=\"$locale\" lang=\"$locale\"";	
 	}
diff --git a/code/model/SiteTree.php b/code/model/SiteTree.php
index e24c1aac..b52a2010 100644
--- a/code/model/SiteTree.php
+++ b/code/model/SiteTree.php
@@ -2464,6 +2464,7 @@ class SiteTree extends DataObject implements PermissionProvider,i18nEntityProvid
 	 * @deprecated 3.0 Use getTreeTitle()
 	 */
 	function TreeTitle() {
+		Deprecation::notice('3.0', 'Use getTreeTitle() instead.');
 		return $this->getTreeTitle();
 	}
 
diff --git a/code/model/SiteTreeDecorator.php b/code/model/SiteTreeDecorator.php
index bea4e5dc..3c5876bb 100644
--- a/code/model/SiteTreeDecorator.php
+++ b/code/model/SiteTreeDecorator.php
@@ -7,11 +7,7 @@
 abstract class SiteTreeDecorator extends SiteTreeExtension {
 
 	public function __construct() {
-		// TODO Re-enable before we release 3.0 beta, for now it "breaks" too many modules
-		// user_error(
-		// 			'SiteTreeDecorator is deprecated, please use SiteTreeExtension instead.',
-		// 			E_USER_NOTICE
-		// 		);
+		Deprecation::notice('3.0', 'Use SiteTreeExtension instead.');
 		parent::__construct();
 	}