diff --git a/doc/eigendoxy.css b/doc/eigendoxy.css
index 9a036d215..225f5d32e 100644
--- a/doc/eigendoxy.css
+++ b/doc/eigendoxy.css
@@ -165,6 +165,8 @@ div.toc {
   bottom:0;
   border-radius:0px;
   border-style: solid none none none;
+  max-height:50%;
+  overflow-y: scroll;
 }
 
 div.toc h3 {