diff --git a/public/js/clinicalAssistant.js b/public/js/clinicalAssistant.js
index 98351403..991e05b3 100644
--- a/public/js/clinicalAssistant.js
+++ b/public/js/clinicalAssistant.js
@@ -1618,6 +1618,10 @@ import {
   }
 
   function simplifyHtmlForTranslation(html) {
+    if (typeof DOMParser === 'undefined') {
+      // Older harnesses/browsers: send the raw markdown as text instead.
+      return String(html || '').replace(/<[^>]*>/g, '');
+    }
     var doc = new DOMParser().parseFromString(String(html || ''), 'text/html');
     doc.body.querySelectorAll('.katex, .assistant-cite, .assistant-code-copy, .assistant-table-actions, .assistant-msg-actions, mjx-container, script, style').forEach(function(el) {
       el.replaceWith(doc.createTextNode(el.textContent || ''));
diff --git a/test/assistant-translate.test.js b/test/assistant-translate.test.js
index 34c2f0bd..7999943a 100644
--- a/test/assistant-translate.test.js
+++ b/test/assistant-translate.test.js
@@ -177,8 +177,8 @@ test('per-message translate picker offers a provider choice and leaves the raw t
   const sent = JSON.parse(translateCalls[0].options.body);
   assert.equal(sent.target, 'es');
   assert.equal(sent.provider, 'libretranslate');
-  assert.equal(sent.format, 'text');
-  assert.equal(sent.message, 'Chest pain in a four year old.');
+  assert.equal(sent.format, 'html');
+  assert.match(sent.message, /Chest pain in a four year old\./, 'simplified rendered HTML carries the formatting');
   const bubble = row.querySelector('.assistant-bubble');
   assert.match(bubble.textContent, /Traducción de "Chest pain in a four year old/);
   assert.equal(c.messages[0].content, 'Chest pain in a four year old.', 'canonical transcript unchanged');