diff --git a/4.0-Upgrade.md b/4.0-Upgrade.md
index b67b727d3..b88dab7c4 100644
--- a/4.0-Upgrade.md
+++ b/4.0-Upgrade.md
@@ -17,7 +17,7 @@ gem 'redis-namespace'
 * **Redis 2.8.0 or greater is required.**  Redis 2.8 was released two years
   ago and contains **many** useful features which Sidekiq couldn't
   leverage until now.  **Redis 3.0.3 or greater is recommended** for large
-  scale use [#2431].
+  scale use [mperham/sidekiq#2431].
 
 * Jobs are now fetched from Redis in parallel, making Sidekiq more
   resilient to high network latency.  This means that Sidekiq requires