diff --git a/src/Handlers/FormSubmission.php b/src/Handlers/FormSubmission.php
index c043cb8..9b3036a 100644
--- a/src/Handlers/FormSubmission.php
+++ b/src/Handlers/FormSubmission.php
@@ -38,6 +38,6 @@ protected function getPasswordCleartextFromSuperglobals(): string
             return '';
         }
 
-        return wp_unslash($_POST['pass1'] ?? $_POST['password_1']); // WPCS: input var, CSRF ok.
+        return (string) wp_unslash($_POST['pass1'] ?? $_POST['password_1']); // WPCS: input var, CSRF ok.
     }
 }