diff --git a/articles/3_tips_for_game_development.html b/articles/3_tips_for_game_development.html
index 89ef06a..ab40c85 100644
--- a/articles/3_tips_for_game_development.html
+++ b/articles/3_tips_for_game_development.html
@@ -257,7 +257,7 @@ <h4>Demo #20</h4>
                 </div>
             </div>
 
-            <div class = demo>
+            <div class = demo id = sub>
                 <p>The best project I made during this period was definitely the
                 simplified platform game. It was created just before
                 <a class = normal href = /content/the_mitigator target = _blank>The Mitigator</a>,
@@ -265,7 +265,7 @@ <h4>Demo #20</h4>
                 which simply means that they're created using randomisation, so they're different
                 every time.</p>
 
-                <div class = subDemo id = sub>
+                <div class = subDemo>
                     <h3>First Platformer</h3>
                     <p><b>Use the arrows or WASD to jump on the platforms and collect the coins.
                     Press R to restart each level. Space to throw shells. Avoid the red squares!