diff --git a/includes/class-ot-meta-box.php b/includes/class-ot-meta-box.php
index 627abda..a0109c8 100755
--- a/includes/class-ot-meta-box.php
+++ b/includes/class-ot-meta-box.php
@@ -207,7 +207,7 @@ public function save_meta_box( $post_id, $post_object ) {
 			global $pagenow;
 
 			// Verify nonce.
-			if ( isset( $_POST[ $this->meta_box['id'] . '_nonce' ] ) && ! wp_verify_nonce( $_POST[ $this->meta_box['id'] . '_nonce' ], $this->meta_box['id'] ) ) { // phpcs:ignore
+			if ( ! isset( $_POST[ $this->meta_box['id'] . '_nonce' ] ) || ! wp_verify_nonce( $_POST[ $this->meta_box['id'] . '_nonce' ], $this->meta_box['id'] ) ) { // phpcs:ignore
 				return $post_id;
 			}