diff --git a/src/proxy-animation.js b/src/proxy-animation.js
index f6c985a3..a54d0e5b 100644
--- a/src/proxy-animation.js
+++ b/src/proxy-animation.js
@@ -784,7 +784,7 @@ function createProxyEffect(details) {
         return;
 
       // Additional validation that is specific to scroll timelines.
-      if (details.timeline) {
+      if (details.timeline && argumentsList[0]) {
         const options = argumentsList[0];
         const duration = options.duration;
         if (duration === Infinity) {