diff --git a/includes/functions.php b/includes/functions.php
index ecb8765..f9d602f 100644
--- a/includes/functions.php
+++ b/includes/functions.php
@@ -279,6 +279,16 @@ function is_activitypub_request() {
 		return false;
 	}
 
+	// Check if the current post type supports ActivityPub.
+	if ( \is_singular() ) {
+		$queried_object = \get_queried_object();
+		$post_type      = \get_post_type( $queried_object );
+
+		if ( ! \post_type_supports( $post_type, 'activitypub' ) ) {
+			return false;
+		}
+	}
+
 	// One can trigger an ActivityPub request by adding ?activitypub to the URL.
 	// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.VariableRedeclaration
 	global $wp_query;