diff --git a/_data/documentation.yml b/_data/documentation.yml
index 4a2acaf..02a6494 100755
--- a/_data/documentation.yml
+++ b/_data/documentation.yml
@@ -38,6 +38,8 @@
           url: http://doxygen.gem5.org/release/v20-1-0-1/index.html
         - page: v20.1.0.5
           url: http://doxygen.gem5.org/release/v20-1-0-5/index.html
+        - page: v21.0.0.0
+          url: http://doxygen.gem5.org/release/v21-0-0-0/index.html
 
     - title: gem5 Resources
       id: gem5_resources