diff --git a/includes/classes/wp-maintenance-mode-admin.php b/includes/classes/wp-maintenance-mode-admin.php
index 62f8845..f57b64b 100644
--- a/includes/classes/wp-maintenance-mode-admin.php
+++ b/includes/classes/wp-maintenance-mode-admin.php
@@ -1182,7 +1182,7 @@ public function add_display_post_states( $post_states, $post ) {
 		 */
 		public function add_wizard_classes( $classes ) {
 			if ( ! get_option( 'wpmm_fresh_install', false ) ) {
-				$classes .= 'wpmm-wizard-fullscreen';
+				$classes .= ' wpmm-wizard-fullscreen';
 			}
 
 			return $classes;