diff --git a/lib/pixi/timeline.js b/lib/pixi/timeline.js
index be4b1fe..4896091 100644
--- a/lib/pixi/timeline.js
+++ b/lib/pixi/timeline.js
@@ -781,6 +781,9 @@ export default class Timeline extends BitmapLabeledGraphics {
 
     onMove(event, interaction) {
         let delta = interaction.delta()
+        if (delta == null) {
+            return
+        }
         this.scroll += delta.x
         while (this.deltas.length > 10) {
             this.deltas.pop(0)