diff --git a/fs_attachment/tests/test_fs_attachment.py b/fs_attachment/tests/test_fs_attachment.py
index e4c70fa320..051646fe71 100644
--- a/fs_attachment/tests/test_fs_attachment.py
+++ b/fs_attachment/tests/test_fs_attachment.py
@@ -51,9 +51,17 @@ def test_create_attachment_with_meaningful_name(self):
         # The storage root is NOT part of the store_fname
         self.assertFalse("tmp/" in attachment.store_fname)
 
+        with attachment.open("rb") as f:
+            file_content = f.read()
+            self.assertEqual(file_content, content)
+
+        new_content = b"new content"
+        with attachment.open("wb") as f:
+            f.write(new_content)
         # we can read the file, so storage finds it correctly
         with attachment.open("rb") as f:
-            self.assertEqual(f.read(), content)
+            file_content = f.read()
+            self.assertEqual(file_content, new_content)
 
     def test_open_attachment_in_db(self):
         self.env["ir.config_parameter"].sudo().set_param("ir_attachment.location", "db")