diff --git a/examples/particle_explorer/particleExplorer.js b/examples/particle_explorer/particleExplorer.js
index f258d55052..41f08a9f7e 100644
--- a/examples/particle_explorer/particleExplorer.js
+++ b/examples/particle_explorer/particleExplorer.js
@@ -60,6 +60,7 @@ var keysToAllow = [
     'colorFinish',
     'alpha',
     'alphaSpread',
+    'alphaStart',
     'alphaFinish',
     'emitterShouldTrail'
 ];