diff --git a/swh/objstorage/objstorage_pathslicing.py b/swh/objstorage/objstorage_pathslicing.py
index 897a5f7..5a897e8 100644
--- a/swh/objstorage/objstorage_pathslicing.py
+++ b/swh/objstorage/objstorage_pathslicing.py
@@ -37,12 +38,6 @@ def _write_obj_file(hex_obj_id, objstorage):
     Yields:
         a file-like object open for writing bytes.
     """
-    # Get the final paths and create the directory if absent.
-    dir = objstorage._obj_dir(hex_obj_id)
-    if not os.path.isdir(dir):
-        os.makedirs(dir, DIR_MODE, exist_ok=True)
-    path = os.path.join(dir, hex_obj_id)
-
     # Create a temporary file.
     (tmp, tmp_path) = tempfile.mkstemp(suffix='.tmp', prefix='hex_obj_id.',
                                        dir=dir)
@@ -54,6 +49,13 @@ def _write_obj_file(hex_obj_id, objstorage):

     # Then close the temporary file and move it to the right directory.
     tmp_f.close()
+
+    # Get the final paths and create the directory if absent.
+    dir = objstorage._obj_dir(hex_obj_id)
+    if not os.path.isdir(dir):
+        os.makedirs(dir, DIR_MODE, exist_ok=True)
+    path = os.path.join(dir, hex_obj_id)
+
     os.chmod(tmp_path, FILE_MODE)
     os.rename(tmp_path, path)