diff --git a/web/templates/entry_view.html b/web/templates/entry_view.html
index 20c5728..2cba0cf 100644
--- a/web/templates/entry_view.html
+++ b/web/templates/entry_view.html
@@ -43,9 +43,9 @@
 <button class="btn btn-secondary" id="ttsBtn"
         title="Read aloud"
         aria-label="Read illustration out loud"
+        {% if tts_url %} data-tts-url="{{ tts_url }}"{% endif %}
         data-illustration="{{ entry.illustration|default_if_none:''|escapejs }}"
         data-application="{{ entry.application|default_if_none:''|escapejs }}">
-  <!-- Speaker icon (inline SVG) -->
   <svg width="16" height="16" viewBox="0 0 24 24" aria-hidden="true" style="vertical-align:middle;">
     <path d="M3 10v4h4l5 4V6L7 10H3z"></path>
     <path d="M16.5 12c0-1.77-1-3.29-2.5-4.03v8.06A4.49 4.49 0 0 0 16.5 12z"></path>