diff --git a/migrate.py b/migrate.py
index c7ef9ce..44e2a46 100644
--- a/migrate.py
+++ b/migrate.py
@@ -178,7 +178,7 @@ def save_split(data, out_dir):
         rendered = item.pop("_rendered_annotations", "")
         name = item["metadata"]["name"]
         namespace = item["metadata"].get("namespace", "default")
-        path = Path(out_dir) / f"{namespace}__{name}.yaml"
+        path = Path(out_dir) / f"{namespace}_{name}.yaml"
 
         with open(path, "w") as f:
             yaml.dump(item, f)