diff --git a/includes/admin/class-health-check.php b/includes/admin/class-health-check.php
index fec797c..00044ec 100644
--- a/includes/admin/class-health-check.php
+++ b/includes/admin/class-health-check.php
@@ -86,6 +86,10 @@ class Health_Check {
 	 * @return bool True if the check passed.
 	 */
 	public static function test_if_event_transformer_is_used( $event_plugin ) {
+		if ( ! Setup::get_instance()->is_activitypub_plugin_active() ) {
+			return false;
+		}
+
 		// Get a (random) event post.
 		$event_posts = self::get_most_recent_event_posts( $event_plugin->get_post_type(), 1 );
 
@@ -113,6 +117,10 @@ class Health_Check {
 	 * @return WP_Post[]|false         Array of event posts, or false if none are found.
 	 */
 	public static function get_most_recent_event_posts( $event_post_type = null, $number_of_posts = 5 ) {
+		if ( ! Setup::get_instance()->is_activitypub_plugin_active() ) {
+			return false;
+		}
+
 		if ( ! $event_post_type ) {
 			$active_event_plugins = Setup::get_instance()->get_active_event_plugins();
 			$active_event_plugin  = reset( $active_event_plugins );