diff --git a/src/main/content/antora_ui/src/sass/nav.scss b/src/main/content/antora_ui/src/sass/nav.scss
index 5ccb4ce78b..791880767a 100644
--- a/src/main/content/antora_ui/src/sass/nav.scss
+++ b/src/main/content/antora_ui/src/sass/nav.scss
@@ -211,6 +211,14 @@ html.is-clipped--nav {
   }
 }
 
+.nav-item[data-depth="3"]{
+  display: block;                   
+  overflow-wrap: break-word;
+  & > a{
+    display: block;
+  }
+}
+
 .nav-item.is-active {
   & > .nav-item-toggle {
     background: transparent url(../img/chevron.svg) no-repeat center / 50%;