diff --git a/src/wp-admin/js/post.js b/src/wp-admin/js/post.js
index 73a685e..8e963ae 100644
--- a/src/wp-admin/js/post.js
+++ b/src/wp-admin/js/post.js
@@ -423,7 +423,13 @@ jQuery(document).ready( function($) {
 			return;
 		}
 
-		if ( $button.hasClass('submitdelete') || $button.is( '#post-preview' ) ) {
+		if ( $button.hasClass( 'submitdelete' ) ){
+			releaseLock = false;
+			$(window).off( 'beforeunload.edit-post' );
+			return;
+		}
+
+		if ( $button.is( '#post-preview' ) ) {
 			return;
 		}