diff --git a/bookwyrm/templates/snippets/reading_modals/form.html b/bookwyrm/templates/snippets/reading_modals/form.html
index d1ba916f..382407ba 100644
--- a/bookwyrm/templates/snippets/reading_modals/form.html
+++ b/bookwyrm/templates/snippets/reading_modals/form.html
@@ -12,4 +12,5 @@
 <input type="hidden" name="user" value="{{ request.user.id }}">
 <input type="hidden" name="mention_books" value="{{ book.id }}">
 <input type="hidden" name="book" value="{{ book.id }}">
+<input type="hidden" name="id" value="{{ readthrough.id }}">
 {% endblock %}