I have a UICollectionView to display photos from a device's album with the Photos framework. The photos are correctly displayed, but if I scroll fast (like when you tape at the top of the screen to go to the top of the collectionView), I have some photos which are not at the good indexPath. I just need to scroll a bit to put the bad photo out of the screen, and everything go back in place.I clean the cell during prepareForReuse by canceling the current request.I presume it's a problem with the asynchronous request of PHImageManager, but I don't know how to avoid this problem. And I want to keet the asynchronous request to keep the collectionView smooth.Here some code :View Controller extension AlbumDetailViewController : UICollectionViewDataSource { func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int { return 1 } func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int { return photoList.count } func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell { let cell = collectionView.dequeueReusableCellWithReuseIdentifier("PhotoCell", forIndexPath: indexPath) as! PhotoCollectionCell cell.setImage(photoList.objectAtIndex(indexPath.row) as! PHAsset) return cell } }Custom CollectionViewCell class PhotoCollectionCell: UICollectionViewCell { @IBOutlet weak var imageView: UIImageView! var requestId: PHImageRequestID! let manager = PHImageManager.defaultManager() override func awakeFromNib() { super.awakeFromNib() // Initialization code } override func prepareForReuse() { self.imageView.image = nil manager.cancelImageRequest(self.requestId) } func setImage(asset: PHAsset) { let option = PHImageRequestOptions() option.resizeMode = .Fast option.deliveryMode = .HighQualityFormat self.requestId = manager.requestImageForAsset(asset, targetSize: CGSize(width: self.frame.size.width * UIScreen.mainScreen().scale, height: self.frame.size.height * UIScreen.mainScreen().scale), contentMode: PHImageContentMode.Default, options: option, resultHandler: {(result, info)->Void in self.imageView.image = result }) } }Thank you