diff --git a/site/_docs/upgrading/2-to-3.md b/site/_docs/upgrading/2-to-3.md
index dbbda9a9..86cd910c 100644
--- a/site/_docs/upgrading/2-to-3.md
+++ b/site/_docs/upgrading/2-to-3.md
@@ -13,6 +13,8 @@ Before we dive in, go ahead and fetch the latest version of Jekyll:
 $ gem update jekyll
 {% endhighlight %}
 
+Please note: Jekyll 3 requires Ruby version >= 2.0.0.
+
 <div class="note feature">
   <h5 markdown="1">Diving in</h5>
   <p markdown="1">Want to get a new Jekyll site up and running quickly? Simply