diff --git a/lib/compat/wordpress-6.8/post.php b/lib/compat/wordpress-6.8/post.php
index 26e6c3adc07a3..639e33b4e5ca5 100644
--- a/lib/compat/wordpress-6.8/post.php
+++ b/lib/compat/wordpress-6.8/post.php
@@ -39,7 +39,7 @@ function gutenberg_post_type_default_rendering_mode( $args, $post_type ) {
 	if (
 		wp_is_block_theme() &&
 		( isset( $args['show_in_rest'] ) && $args['show_in_rest'] ) &&
-		( isset( $args['supports'] ) && in_array( 'editor', $args['supports'], true ) )
+		( ! empty( $args['supports'] ) && in_array( 'editor', $args['supports'], true ) )
 	) {
 		// Validate the supplied rendering mode.
 		if (