diff --git a/nac3standalone/demo/src/loop.py b/nac3standalone/demo/src/loop.py
index da353239..41293652 100644
--- a/nac3standalone/demo/src/loop.py
+++ b/nac3standalone/demo/src/loop.py
@@ -6,4 +6,4 @@ def run() -> int32:
     for _ in range(10):
         output_int32(_)
         _ = 0
-
+    return 0