diff --git a/test/index.html b/test/index.html
index 06b9845fd..03f51bf82 100644
--- a/test/index.html
+++ b/test/index.html
@@ -58,6 +58,7 @@
     <script src='spec/actions/split.js'></script>
     <script src='spec/actions/straighten.js'></script>
     <script src='spec/actions/unrestrict_turn.js'></script>
+    <script src='spec/actions/flip.js'></script>
 
     <script src='spec/behavior/hash.js'></script>
     <script src='spec/behavior/hover.js'></script>