diff --git a/src/blog.ml b/src/blog.ml
index 1c08945..db420cf 100644
--- a/src/blog.ml
+++ b/src/blog.ml
@@ -586,9 +586,9 @@ struct
 
     let open Task in
     let compute_index =
-      let rec filter = function
+      let filter = function
         | [] | [_] | [_; _] | [_; _; _] as latest_three -> latest_three
-        | _too_old :: more_recent -> filter more_recent
+        | newest :: newer :: new_ :: _old -> [newest; newer; new_]
       in
       Articles.compute_index
         ~filter