diff --git a/nominatim/tools/convert_sqlite.py b/nominatim/tools/convert_sqlite.py
index 59c8e7687f..758fb7b254 100644
--- a/nominatim/tools/convert_sqlite.py
+++ b/nominatim/tools/convert_sqlite.py
@@ -74,7 +74,8 @@ async def copy_data(self) -> None:
                        if isinstance(c.type, Geometry) else c
                        for c in self.inconn.t.meta.tables[table.name].c]
             data = []
-            for row in await self.inconn.execute(sa.select(*columns)):
+            async_result = await self.inconn.connection.stream(sa.select(*columns))
+            async for row in async_result:
                 params = row._asdict()
                 if 'class' in params:
                     params['class_'] = params['class']