diff --git a/src/containers/costume-tab.jsx b/src/containers/costume-tab.jsx
index cfaa3bd96d895116d3121b06dfce337ca8dfa515..39e0419acdd720dec654f37bf9244dfe2014e573 100644
--- a/src/containers/costume-tab.jsx
+++ b/src/containers/costume-tab.jsx
@@ -154,7 +154,7 @@ class CostumeTab extends React.Component {
     }
     handleExportCostume (costumeIndex) {
         const item = this.props.vm.editingTarget.sprite.costumes[costumeIndex];
-        const blob = new Blob([item.asset.data], {type: item.asset.contentType});
+        const blob = new Blob([item.asset.data], {type: item.asset.assetType.contentType});
         downloadBlob(`${item.name}.${item.asset.dataFormat}`, blob);
     }
     handleNewCostume (costume, fromCostumeLibrary) {
diff --git a/src/containers/sound-tab.jsx b/src/containers/sound-tab.jsx
index 4f497e1876fb4bf3462d518708e403a55a8c0caa..3880de2e5349d3df811651a96846cb5c9b06e1a8 100644
--- a/src/containers/sound-tab.jsx
+++ b/src/containers/sound-tab.jsx
@@ -90,7 +90,7 @@ class SoundTab extends React.Component {
 
     handleExportSound (soundIndex) {
         const item = this.props.vm.editingTarget.sprite.sounds[soundIndex];
-        const blob = new Blob([item.asset.data], {type: item.asset.contentType});
+        const blob = new Blob([item.asset.data], {type: item.asset.assetType.contentType});
         downloadBlob(`${item.name}.${item.asset.dataFormat}`, blob);
     }