diff --git a/pages/customprompts/mzta-custom-prompts.js b/pages/customprompts/mzta-custom-prompts.js
index 49dc6376..e61d392c 100644
--- a/pages/customprompts/mzta-custom-prompts.js
+++ b/pages/customprompts/mzta-custom-prompts.js
@@ -333,6 +333,7 @@ function toggleDiffviewer(e) {
         checkbox.disabled = false;
     } else {
         checkbox.checked = false;
+        checkbox.setAttribute('checked_val', '0');
         checkbox.disabled = true;
     }
     //console.log('>>>>>>>> tr: ' + tr.getAttribute('data-idnum'));