diff --git a/align_data/common/alignment_dataset.py b/align_data/common/alignment_dataset.py
index 06da73d..91db5ac 100644
--- a/align_data/common/alignment_dataset.py
+++ b/align_data/common/alignment_dataset.py
@@ -109,9 +109,9 @@ def commit() -> bool:
                 session.rollback()
                 return False
 
-        with make_session() as session:
-            items = iter(entries)
-            while batch := tuple(islice(items, self.batch_size)):
+        items = iter(entries)
+        while batch := tuple(islice(items, self.batch_size)):
+            with make_session() as session:
                 self._add_batch(session, batch)
                 # there might be duplicates in the batch, so if they cause
                 # an exception, try to commit them one by one