diff --git a/core/Object.php b/core/Object.php
index 864366eab..519182f44 100755
--- a/core/Object.php
+++ b/core/Object.php
@@ -41,10 +41,11 @@ abstract class Object {
 	 */
 	
 	private static
-		$statics          = array(),
-		$cached_statics   = array(),
-		$extra_statics    = array(),
-		$replaced_statics = array();
+		$statics                 = array(),
+		$cached_statics          = array(),
+		$extra_statics           = array(),
+		$replaced_statics        = array(),
+		$_cache_statics_prepared = array();
 	
 	private static
 		$classes_constructed = array(),
@@ -171,6 +172,11 @@ abstract class Object {
 	 */
 	public static function get_static($class, $name, $uncached = false) {
 		if(!isset(self::$cached_statics[$class][$name]) || $uncached) {
+			if(!isset(self::$_cache_statics_prepared[$class])) {
+				Object::prepare_statics($class);
+			}
+			
+			//if($class == 'DataObjectDecoratorTest_MyObject') Debug::message("$class - $name");
 			$extra     = $builtIn = $break = $replacedAt = false;
 			$ancestry  = array_reverse(ClassInfo::ancestry($class));
 			
@@ -234,6 +240,10 @@ abstract class Object {
 	 * @param mixed $value
 	 */
 	public static function set_static($class, $name, $value) {
+		if(!isset(self::$_cache_statics_prepared[$class])) {
+			Object::prepare_statics($class);
+		}
+
 		self::$statics[$class][$name]        = $value;
 		self::$cached_statics[$class][$name] = true;
 	}
@@ -396,6 +406,28 @@ abstract class Object {
 			DataObjectDecorator::load_extra_statics($class, $extensionClass);
 		}
 	}
+
+	/**
+	 * Prepare static variables before processing a {@link get_static} or {@link set_static}
+	 * call.
+	 */
+	private static function prepare_statics($class) {
+		// _cache_statics_prepared setting must come first to prevent infinite loops when we call
+		// get_static below
+		self::$_cache_statics_prepared[$class] = true;
+
+		// load statics now for DataObject classes
+		if(is_subclass_of($class, 'DataObject')) {
+			$extensions = Object::get_static($class, 'extensions');
+			if($extensions) foreach($extensions as $extension) {
+				if(preg_match('/^([^(]*)/', $extension, $matches)) {
+					$extensionClass = $matches[1];
+					DataObjectDecorator::load_extra_statics($class, $extensionClass);
+				}
+			}
+		}
+	}
+	
 	
 	/**
 	 * Remove an extension from a class.
diff --git a/core/model/SiteTree.php b/core/model/SiteTree.php
index b2254f611..f0220e877 100644
--- a/core/model/SiteTree.php
+++ b/core/model/SiteTree.php
@@ -1955,10 +1955,4 @@ class SiteTree extends DataObject implements PermissionProvider,i18nEntityProvid
 
 }
 
-// Workaround for issues with extensions defined directly on the class in trunk
-if(method_exists('DataObjectDecorator', 'load_extra_statics')) {
-	DataObjectDecorator::load_extra_statics('SiteTree', 'Hierarchy');
-	DataObjectDecorator::load_extra_statics('SiteTree', 'Versioned');
-}
-
 ?>
\ No newline at end of file
diff --git a/filesystem/File.php b/filesystem/File.php
index 1753946ac..7488ea0a4 100755
--- a/filesystem/File.php
+++ b/filesystem/File.php
@@ -617,9 +617,4 @@ class File extends DataObject {
 	
 }
 
-// Workaround for issues with extensions defined directly on the class in trunk
-if(method_exists('DataObjectDecorator', 'load_extra_statics')) {
-	DataObjectDecorator::load_extra_statics('File', 'Hierarchy');
-}
-
 ?>
diff --git a/security/Group.php b/security/Group.php
index cff104f01..6994c6662 100644
--- a/security/Group.php
+++ b/security/Group.php
@@ -387,10 +387,5 @@ class Group extends DataObject {
 		return false;
 	}
 }
-
-// Workaround for issues with extensions defined directly on the class in trunk
-if(method_exists('DataObjectDecorator', 'load_extra_statics')) {
-	DataObjectDecorator::load_extra_statics('Group', 'Hierarchy');
-}
 	
 ?>