diff --git a/common/lib/capa/capa/templates/textinput.html b/common/lib/capa/capa/templates/textinput.html
index d2059fdc58..3685742a3c 100644
--- a/common/lib/capa/capa/templates/textinput.html
+++ b/common/lib/capa/capa/templates/textinput.html
@@ -48,6 +48,9 @@
 
       % if do_math:
       <div id="display_${id}" class="equation">`{::}`</div>
+      <textarea style="display:none" id="input_${id}_dynamath" name="input_${id}_dynamath">
+      </textarea>
+
       % endif
 
 % if state in ['unsubmitted', 'correct', 'incorrect', 'incomplete']: