diff --git a/django/contrib/admindocs/templates/admin_doc/model_index.html b/django/contrib/admindocs/templates/admin_doc/model_index.html
index 702fdff3294..4dd7caa2a6e 100644
--- a/django/contrib/admindocs/templates/admin_doc/model_index.html
+++ b/django/contrib/admindocs/templates/admin_doc/model_index.html
@@ -14,7 +14,7 @@
 <div id="content-main">
 {% for group in grouped_models %}
 <div class="module">
-<h2 id="{{ group.grouper }}">{{ group.grouper|capfirst }}</h2>
+<h2 id="app-{{ group.grouper }}">{{ group.grouper|capfirst }}</h2>
 
 <table class="xfull">
 {% for model in group.list %}