diff --git a/includes/class-activity-dispatcher.php b/includes/class-activity-dispatcher.php
index 37c3f86..122ed04 100644
--- a/includes/class-activity-dispatcher.php
+++ b/includes/class-activity-dispatcher.php
@@ -65,8 +65,8 @@ class Activity_Dispatcher {
 			return;
 		}
 
-		$transformer = Transformers_Manager::get_transformer( $wp_post );
-		$transformer->transform( $wp_post );
+		$transformer = \Activitypub\Transformers_Manager::instance()->get_transformer( $wp_post );
+		$transformer->set_wp_post( $wp_post );
 		$transformer->to_object();
 
 		$activity = new Activity();
@@ -103,8 +103,8 @@ class Activity_Dispatcher {
 			return;
 		}
 
-		$transformer = Transformers_Manager::get_transformer( $wp_post );
-		$transformer->transform( $wp_post );
+		$transformer = \Activitypub\Transformers_Manager::instance()->get_transformer( $wp_post );
+		$transformer->set_wp_post( $wp_post );
 		$transformer->to_object();
 
 		$activity = new Activity();
diff --git a/includes/rest/class-collection.php b/includes/rest/class-collection.php
index e383d3b..98395d0 100644
--- a/includes/rest/class-collection.php
+++ b/includes/rest/class-collection.php
@@ -168,7 +168,7 @@ class Collection {
 		);
 
 		foreach ( $posts as $post ) {
-			$response['orderedItems'][] = Transformers_Manager::get_transformer( $post )->transform( $post )->to_object()->to_array();
+			$response['orderedItems'][] = Transformers_Manager::instance()->get_transformer( $post )->set_wp_post( $wp_post )->to_object()->to_array();
 		}
 
 		$rest_response = new WP_REST_Response( $response, 200 );
diff --git a/includes/rest/class-outbox.php b/includes/rest/class-outbox.php
index a9ebc63..9b0a1c2 100644
--- a/includes/rest/class-outbox.php
+++ b/includes/rest/class-outbox.php
@@ -105,8 +105,8 @@ class Outbox {
 			);
 
 			foreach ( $posts as $post ) {
-				$transformer = Transformers_Manager::get_transformer( $wp_post );
-				$transformer->transform( $wp_post );
+				$transformer = \Activitypub\Transformers_Manager::instance()->get_transformer( $post );
+				$transformer->set_wp_post( $wp_post );
 				$post = $transformer->to_object();
 				$activity = new Activity();
 				$activity->set_type( 'Create' );
diff --git a/tests/test-class-activitypub-activity.php b/tests/test-class-activitypub-activity.php
index 70ddb33..d8c2b5d 100644
--- a/tests/test-class-activitypub-activity.php
+++ b/tests/test-class-activitypub-activity.php
@@ -18,7 +18,7 @@ class Test_Activitypub_Activity extends WP_UnitTestCase {
 		);
 		
 		$wp_post = get_post( $post );
-		$activitypub_post = \Activitypub\Transformers_Manager::get_transforemr( $wp_post )->transform( $wp_post )->to_object();
+		$activitypub_post = \Activitypub\Transformers_Manager::instance()->get_transformer( $post )->set_wp_post( $wp_post )->to_object();
 
 		$activitypub_activity = new \Activitypub\Activity\Activity();
 		$activitypub_activity->set_type( 'Create' );
diff --git a/tests/test-class-activitypub-post.php b/tests/test-class-activitypub-post.php
index eccd6bc..d3b6a7c 100644
--- a/tests/test-class-activitypub-post.php
+++ b/tests/test-class-activitypub-post.php
@@ -10,13 +10,13 @@ class Test_Activitypub_Post extends WP_UnitTestCase {
 
 		$permalink = \get_permalink( $post );
 
-		$activitypub_post = \Activitypub\Transformers_Manager::get_transformer( get_post( $post ) )->transform( get_post( $post ) )->to_object();
+		$activitypub_post = \Activitypub\Transformers_Manager::instance()->get_transformer( get_post( $post ) )->set_wp_post( get_post( $post ) )->to_object();
 
 		$this->assertEquals( $permalink, $activitypub_post->get_id() );
 
 		\wp_trash_post( $post );
 
-		$activitypub_post = \Activitypub\Transformers_Manager::get_transformer( get_post( $post ) )->transform( get_post( $post ) )->to_object();
+		$activitypub_post = \Activitypub\Transformers_Manager::instance()->get_transformer( get_post( $post ) )->set_wp_post( get_post( $post ) )->to_object();
 
 		$this->assertEquals( $permalink, $activitypub_post->get_id() );
 
diff --git a/tests/test-class-activitypub-rest-post-signature-verification.php b/tests/test-class-activitypub-rest-post-signature-verification.php
index 2da383b..e70df19 100644
--- a/tests/test-class-activitypub-rest-post-signature-verification.php
+++ b/tests/test-class-activitypub-rest-post-signature-verification.php
@@ -10,7 +10,7 @@ class Test_Activitypub_Signature_Verification extends WP_UnitTestCase {
 			)
 		);
 		$remote_actor = \get_author_posts_url( 2 );
-		$activitypub_post = \Activitypub\Transformers_Manager::get_transformer( get_post( $post ) )->transform( get_post( $post ) )->to_object();
+		$activitypub_post = \Activitypub\Transformers_Manager::instance()->get_transformer( get_post( $post ) )->set_wp_post( get_post( $post ) )->to_object();
 		$activitypub_activity = new Activitypub\Activity\Activity( 'Create' );
 		$activitypub_activity->set_type( 'Create' );
 		$activitypub_activity->set_object( $activitypub_post );
@@ -82,7 +82,7 @@ class Test_Activitypub_Signature_Verification extends WP_UnitTestCase {
 		);
 		$remote_actor = \get_author_posts_url( 2 );
 		$remote_actor_inbox = Activitypub\get_rest_url_by_path( '/inbox' );
-		$activitypub_post = \Activitypub\Transformers_Manager::get_transformer( get_post( $post ) )->transform( get_post( $post ) )->to_object();
+		$activitypub_post = \Activitypub\Transformers_Manager::instance()->get_transformer( get_post( $post )  )->set_wp_post( get_post( $post )  )->to_object();
 		$activitypub_activity = new Activitypub\Activity\Activity();
 		$activitypub_activity->set_type( 'Create' );
 		$activitypub_activity->set_object( $activitypub_post );