diff --git a/crates/meilitool/src/upgrade/v1_12.rs b/crates/meilitool/src/upgrade/v1_12.rs
index 77060d90d..85fb41472 100644
--- a/crates/meilitool/src/upgrade/v1_12.rs
+++ b/crates/meilitool/src/upgrade/v1_12.rs
@@ -69,6 +69,7 @@ fn convert_update_files(db_path: &Path) -> anyhow::Result<()> {
             "while flushing update file bufwriter for update file {update_file_path:?}"
         ))?;
         let _ = file
+            // atomically replace the obkv file with the rewritten NDJSON file
             .persist(&update_file_path)
             .with_context(|| format!("while persisting update file {update_file_path:?}"))?;
     }