diff --git a/AsyncDisplayKit/ASVideoNode.h b/AsyncDisplayKit/ASVideoNode.h
index 178ceff5c7..e525d1a2dc 100644
--- a/AsyncDisplayKit/ASVideoNode.h
+++ b/AsyncDisplayKit/ASVideoNode.h
@@ -41,6 +41,11 @@ NS_ASSUME_NONNULL_BEGIN
 - (BOOL)isPlaying;
 
 @property (nullable, nonatomic, strong, readwrite) AVAsset *asset;
+/**
+ ** @abstract The URL with which the asset was initialized.
+ ** @discussion Setting the URL will overwrite the current asset with a newly created AVURLAsset created from the given URL, and AVAsset *asset will point to that newly created AVURLAsset.  Please don't set both assetURL and asset.
+ ** @return Current URL the asset was initialized or nil if no URL was given.
+ **/
 @property (nullable, nonatomic, strong, readwrite) NSURL *assetURL;
 @property (nullable, nonatomic, strong, readwrite) AVVideoComposition *videoComposition;
 @property (nullable, nonatomic, strong, readwrite) AVAudioMix *audioMix;
diff --git a/AsyncDisplayKit/ASVideoNode.mm b/AsyncDisplayKit/ASVideoNode.mm
index 8771e703d9..5f679f5cc1 100644
--- a/AsyncDisplayKit/ASVideoNode.mm
+++ b/AsyncDisplayKit/ASVideoNode.mm
@@ -442,6 +442,8 @@ static NSString * const kStatus = @"status";
 
 - (void)setAssetURL:(NSURL *)assetURL
 {
+  ASDN::MutexLocker l(__instanceLock__);
+
   if (!ASObjectIsEqual(assetURL, self.assetURL)) {
      self.asset = [AVURLAsset assetWithURL:assetURL];
   }