diff --git a/src/cleanup.js b/src/cleanup.js
index 3699180a..d3172c46 100644
--- a/src/cleanup.js
+++ b/src/cleanup.js
@@ -1,9 +1,6 @@
-import flushMicroTasks from './flush-microtasks'
-
 let cleanupCallbacks = []
 
 async function cleanup() {
-  await flushMicroTasks()
   for (const callback of cleanupCallbacks) {
     await callback()
   }
diff --git a/src/flush-microtasks.js b/src/flush-microtasks.js
deleted file mode 100644
index 0869dfef..00000000
--- a/src/flush-microtasks.js
+++ /dev/null
@@ -1,50 +0,0 @@
-/* istanbul ignore file */
-// the part of this file that we need tested is definitely being run
-// and the part that is not cannot easily have useful tests written
-// anyway. So we're just going to ignore coverage for this file
-/**
- * copied from React's enqueueTask.js
- * copied again from React Testing Library's flush-microtasks.js
- */
-
-let didWarnAboutMessageChannel = false
-let enqueueTask
-try {
-  // read require off the module object to get around the bundlers.
-  // we don't want them to detect a require and bundle a Node polyfill.
-  const requireString = `require${Math.random()}`.slice(0, 7)
-  const nodeRequire = module && module[requireString]
-  // assuming we're in node, let's try to get node's
-  // version of setImmediate, bypassing fake timers if any.
-  enqueueTask = nodeRequire.call(module, 'timers').setImmediate
-} catch (_err) {
-  // we're in a browser
-  // we can't use regular timers because they may still be faked
-  // so we try MessageChannel+postMessage instead
-  enqueueTask = (callback) => {
-    const supportsMessageChannel = typeof MessageChannel === 'function'
-    if (supportsMessageChannel) {
-      const channel = new MessageChannel()
-      channel.port1.onmessage = callback
-      channel.port2.postMessage(undefined)
-    } else if (didWarnAboutMessageChannel === false) {
-      didWarnAboutMessageChannel = true
-
-      // eslint-disable-next-line no-console
-      console.error(
-        'This browser does not have a MessageChannel implementation, ' +
-          'so enqueuing tasks via await act(async () => ...) will fail. ' +
-          'Please file an issue at https://github.com/facebook/react/issues ' +
-          'if you encounter this warning.'
-      )
-    }
-  }
-}
-
-export default function flushMicroTasks() {
-  return {
-    then(resolve) {
-      enqueueTask(resolve)
-    }
-  }
-}