diff --git a/bookwyrm/templates/snippets/reading_modals/progress_update_modal.html b/bookwyrm/templates/snippets/reading_modals/progress_update_modal.html
index 919d2100..e0be1588 100644
--- a/bookwyrm/templates/snippets/reading_modals/progress_update_modal.html
+++ b/bookwyrm/templates/snippets/reading_modals/progress_update_modal.html
@@ -10,6 +10,7 @@
 <form name="reading-progress-{{ uuid }}" action="{% url 'reading-status-update' book.id %}" method="POST" class="submit-status">
 {% csrf_token %}
 <input type="hidden" name="id" value="{{ readthrough.id }}">
+<input type="hidden" name="start_date" value="{{ readthrough.start_date|date:'Y-m-d' }}">
 {% endblock %}
 
 {% block reading-dates %}