diff --git a/bin/baseline.neon b/bin/baseline.neon
index 43377944..b5e73342 100644
--- a/bin/baseline.neon
+++ b/bin/baseline.neon
@@ -1,41 +1,5 @@
 parameters:
 	ignoreErrors:
-		-
-			message: '#^Access to an undefined property ACF_Admin_Field_Groups\:\:\$not_found_label\.$#'
-			identifier: property.notFound
-			count: 1
-			path: ../includes/admin/post-types/admin-field-groups.php
-
-		-
-			message: '#^Action callback returns array but should not return anything\.$#'
-			identifier: return.void
-			count: 1
-			path: ../includes/admin/post-types/admin-field-groups.php
-
-		-
-			message: '#^Class ACF_Admin_Post_type referenced with incorrect case\: ACF_Admin_Post_Type\.$#'
-			identifier: class.nameCase
-			count: 1
-			path: ../includes/admin/post-types/admin-post-type.php
-
-		-
-			message: '#^Access to an undefined property ACF_Admin_Post_Types\:\:\$not_found_label\.$#'
-			identifier: property.notFound
-			count: 1
-			path: ../includes/admin/post-types/admin-post-types.php
-
-		-
-			message: '#^Access to an undefined property ACF_Admin_Taxonomies\:\:\$not_found_label\.$#'
-			identifier: property.notFound
-			count: 1
-			path: ../includes/admin/post-types/admin-taxonomies.php
-
-		-
-			message: '#^Access to an undefined property ACF_Admin_UI_Options_Pages\:\:\$not_found_label\.$#'
-			identifier: property.notFound
-			count: 1
-			path: ../includes/admin/post-types/class-acf-admin-ui-options-pages.php
-
 		-
 			message: '#^Variable \$field might not be defined\.$#'
 			identifier: variable.undefined
diff --git a/includes/admin/admin-internal-post-type-list.php b/includes/admin/admin-internal-post-type-list.php
index ecfa52f2..4364bada 100644
--- a/includes/admin/admin-internal-post-type-list.php
+++ b/includes/admin/admin-internal-post-type-list.php
@@ -69,6 +69,13 @@ class ACF_Admin_Internal_Post_Type_List {
 		 */
 		public $is_pro_feature = false;
 
+		/**
+		 * The label for the "not found" message.
+		 *
+		 * @var string
+		 */
+		public $not_found_label = '';
+
 		/**
 		 * Constructs the class.
 		 */
diff --git a/includes/admin/post-types/admin-field-groups.php b/includes/admin/post-types/admin-field-groups.php
index 9df4e244..e1f88174 100644
--- a/includes/admin/post-types/admin-field-groups.php
+++ b/includes/admin/post-types/admin-field-groups.php
@@ -40,7 +40,7 @@ class ACF_Admin_Field_Groups extends ACF_Admin_Internal_Post_Type_List {
 		public function __construct() {
 			add_action( 'admin_menu', array( $this, 'admin_menu' ), 7 );
 			add_action( 'load-edit.php', array( $this, 'handle_redirection' ) );
-			add_action( 'post_class', array( $this, 'get_admin_table_post_classes' ), 10, 3 );
+			add_filter( 'post_class', array( $this, 'get_admin_table_post_classes' ), 10, 3 );
 
 			parent::__construct();
 		}
diff --git a/includes/admin/post-types/admin-post-type.php b/includes/admin/post-types/admin-post-type.php
index d90031ff..04a30b52 100644
--- a/includes/admin/post-types/admin-post-type.php
+++ b/includes/admin/post-types/admin-post-type.php
@@ -15,7 +15,7 @@
 	 *
 	 * All the logic for editing a post type.
 	 */
-	class ACF_Admin_Post_type extends ACF_Admin_Internal_Post_Type {
+	class ACF_Admin_Post_Type extends ACF_Admin_Internal_Post_Type {
 
 		/**
 		 * The slug for the internal post type.