diff --git a/judge/forms.py b/judge/forms.py
index 5168240..077728a 100644
--- a/judge/forms.py
+++ b/judge/forms.py
@@ -149,19 +149,21 @@ class ProblemSubmitForm(ModelForm):
 
     def clean(self):
         if "source_file" in self.files:
-            if self.cleaned_data["language"].key == "OUTPUT" and self.files[
-                "source_file"
-            ].name.endswith(".zip"):
-                self.source_file_name = secrets.token_hex(16) + ".zip"
-                filepath = os.path.join(
-                    settings.DMOJ_SUBMISSION_ROOT, self.source_file_name
-                )
-                with open(filepath, "wb+") as destination:
-                    for chunk in self.files["source_file"].chunks():
-                        destination.write(chunk)
-                self.cleaned_data["source"] = self.request.build_absolute_uri(
-                    reverse("submission_source_file", args=(self.source_file_name,))
-                )
+            if self.cleaned_data["language"].key in ["OUTPUT", "SCAT"]:
+                filename = self.files["source_file"].name
+                if filename.endswith(".zip") or filename.endswith(".sb3"):
+                    self.source_file_name = (
+                        secrets.token_hex(16) + "." + filename.split(".")[-1]
+                    )
+                    filepath = os.path.join(
+                        settings.DMOJ_SUBMISSION_ROOT, self.source_file_name
+                    )
+                    with open(filepath, "wb+") as destination:
+                        for chunk in self.files["source_file"].chunks():
+                            destination.write(chunk)
+                    self.cleaned_data["source"] = self.request.build_absolute_uri(
+                        reverse("submission_source_file", args=(self.source_file_name,))
+                    )
             del self.files["source_file"]
         return self.cleaned_data
 
diff --git a/templates/problem/submit.html b/templates/problem/submit.html
index 7f36406..178f2ac 100644
--- a/templates/problem/submit.html
+++ b/templates/problem/submit.html
@@ -153,9 +153,15 @@
             if (file.name.endsWith('zip')) {
               update_submit_area(file.name);
             }
-            else if (file.name.endsWith('sb3')) {
-              get_source_scratch(file);
-            }
+            {% if output_only %}
+              else if (file.name.endsWith('sb3')) {
+                update_submit_area(file.name);
+              }
+            {% else %}
+              else if (file.name.endsWith('sb3')) {
+                get_source_scratch(file);
+              }
+            {% endif %}
             else {
               get_source_default(file);
             }