diff --git a/kurt/scratch14/__init__.py b/kurt/scratch14/__init__.py
index f15a194..4291806 100644
--- a/kurt/scratch14/__init__.py
+++ b/kurt/scratch14/__init__.py
@@ -149,12 +149,14 @@ def save(self, fp, project):
         self.stage = self.UserObject("ScratchStageMorph")
 
         # project info
-        thumbnail = self.save_image(
-                kurt.Costume("thumbnail", self.project.thumbnail))
+        thumbnail = self.save_image(kurt.Costume("thumbnail", (
+                self.project.thumbnail or kurt.Image.new((160, 120), (1, 1, 1))
+            ))).form
+
         self.info = {
             'author': self.project.author,
             'comment': self.project.notes.replace("\n", "\r"),
-            'thumbnail': thumbnail.form if thumbnail else None,
+            'thumbnail': thumbnail,
             'history': '',
             'language': 'en',
             'os-version': '',