diff --git a/js/tinymce-integration.js b/js/tinymce-integration.js
index f6de65a..76e1c75 100644
--- a/js/tinymce-integration.js
+++ b/js/tinymce-integration.js
@@ -140,6 +140,10 @@
     },
 
     detach: function (element, format, trigger) {
+      if (trigger === 'submit') {
+        // New trigger type as of core 1.34.3.
+        return;
+      }
       if (trigger === 'serialize') {
         tinymce.triggerSave();
         return;