diff --git a/django/contrib/admin/static/admin/css/nav_sidebar.css b/django/contrib/admin/static/admin/css/nav_sidebar.css
index d599299b55..12f0471bb0 100644
--- a/django/contrib/admin/static/admin/css/nav_sidebar.css
+++ b/django/contrib/admin/static/admin/css/nav_sidebar.css
@@ -71,6 +71,7 @@
 
 #nav-sidebar .module th {
     width: 100%;
+    overflow-wrap: anywhere;
 }
 
 #nav-sidebar .module th,
diff --git a/docs/releases/3.1.1.txt b/docs/releases/3.1.1.txt
index 4ccd0e3718..516d47cd03 100644
--- a/docs/releases/3.1.1.txt
+++ b/docs/releases/3.1.1.txt
@@ -11,3 +11,6 @@ Bugfixes
 
 * Fixed wrapping of translated action labels in the admin's navigation sidebar
   for East Asian languages (:ticket:`31853`).
+
+* Fixed wrapping of long model names in the admin's navigation sidebar
+  (:ticket:`31854`).