diff --git a/src/import/load-costume.js b/src/import/load-costume.js
index 54962ea1f..d435129b2 100644
--- a/src/import/load-costume.js
+++ b/src/import/load-costume.js
@@ -32,7 +32,7 @@ const loadCostume = function (md5ext, costume, runtime) {
 
     let promise = runtime.storage.load(assetType, md5, ext).then(costumeAsset => {
         costume.assetId = costumeAsset.assetId;
-        costume.assetType = assetType;
+        costume.dataFormat = ext;
         return costumeAsset;
     });
 
diff --git a/src/import/load-sound.js b/src/import/load-sound.js
index 80b595987..295b87ebe 100644
--- a/src/import/load-sound.js
+++ b/src/import/load-sound.js
@@ -24,7 +24,7 @@ const loadSound = function (sound, runtime) {
     return runtime.storage.load(runtime.storage.AssetType.Sound, md5, ext)
         .then(soundAsset => {
             sound.assetId = soundAsset.assetId;
-            sound.assetType = runtime.storage.AssetType.Sound;
+            sound.dataFormat = ext;
             return runtime.audioEngine.decodeSound(Object.assign(
                 {},
                 sound,