diff --git a/src/serialization/deserialize-assets.js b/src/serialization/deserialize-assets.js
index be48db12b..bf59f915f 100644
--- a/src/serialization/deserialize-assets.js
+++ b/src/serialization/deserialize-assets.js
@@ -26,7 +26,13 @@ const deserializeSound = function (sound, runtime, zip, assetFileName) {
         return Promise.resolve(null);
     }
 
-    const soundFile = zip.file(fileName);
+    let soundFile = zip.file(fileName);
+    if (!soundFile) {
+        // look for assetfile in a flat list of files, or in a folder
+        const fileMatch = new RegExp(`^([^/]*/)?${fileName}$`);
+        soundFile = zip.file(fileMatch)[0]; // use first matching file
+    }
+
     if (!soundFile) {
         log.error(`Could not find sound file associated with the ${sound.name} sound.`);
         return Promise.resolve(null);
@@ -100,7 +106,13 @@ const deserializeCostume = function (costume, runtime, zip, assetFileName, textL
         return Promise.resolve(null);
     }
 
-    const costumeFile = zip.file(fileName);
+    let costumeFile = zip.file(fileName);
+    if (!costumeFile) {
+        // look for assetfile in a flat list of files, or in a folder
+        const fileMatch = new RegExp(`^([^/]*/)?${fileName}$`);
+        costumeFile = zip.file(fileMatch)[0]; // use the first matched file
+    }
+
     if (!costumeFile) {
         log.error(`Could not find costume file associated with the ${costume.name} costume.`);
         return Promise.resolve(null);