diff --git a/src/app/app.ts b/src/app/app.ts
index eebf26ed..a4e8f84d 100644
--- a/src/app/app.ts
+++ b/src/app/app.ts
@@ -25,7 +25,7 @@ export class App<T extends typeof Component = any> extends TemplateSet {
   Root: T;
   props: any;
   env: Env;
-  scheduler = new Scheduler(window.requestAnimationFrame.bind(window));
+  scheduler = new Scheduler();
   root: ComponentNode | null = null;
 
   constructor(Root: T, config: AppConfig = {}) {
diff --git a/src/component/scheduler.ts b/src/component/scheduler.ts
index 2b868d08..3a8e4be4 100644
--- a/src/component/scheduler.ts
+++ b/src/component/scheduler.ts
@@ -7,11 +7,14 @@ import { STATUS } from "./status";
 // -----------------------------------------------------------------------------
 
 export class Scheduler {
+  // capture the value of requestAnimationFrame as soon as possible, to avoid
+  // interactions with other code, such as test frameworks that override them
+  static requestAnimationFrame = window.requestAnimationFrame.bind(this);
   tasks: Set<RootFiber> = new Set();
   isRunning: boolean = false;
   requestAnimationFrame: Window["requestAnimationFrame"];
 
-  constructor(requestAnimationFrame: Window["requestAnimationFrame"]) {
+  constructor() {
     this.requestAnimationFrame = requestAnimationFrame;
   }