diff --git a/torba/client/basedatabase.py b/torba/client/basedatabase.py
index 28d0901c0..106e3e1d5 100644
--- a/torba/client/basedatabase.py
+++ b/torba/client/basedatabase.py
@@ -35,6 +35,11 @@ class AIOSQLite:
         self.connection = None
         return asyncio.get_event_loop_policy().get_event_loop().call_later(0.01, __close, conn)
 
+    def executemany(self, sql: str, params: Iterable):
+        def __executemany_in_a_transaction(conn: sqlite3.Connection, *args, **kwargs):
+            return conn.executemany(*args, **kwargs)
+        return self.run(__executemany_in_a_transaction, sql, params)
+
     def executescript(self, script: str) -> Awaitable:
         return wrap_future(self.executor.submit(self.connection.executescript, script))
 
@@ -321,12 +326,8 @@ class BaseDatabase(SQLiteMixin):
         return self.db.run(_transaction, tx, address, txhash, history)
 
     async def reserve_outputs(self, txos, is_reserved=True):
-        txoids = [txo.id for txo in txos]
-        await self.db.execute(
-            "UPDATE txo SET is_reserved = ? WHERE txoid IN ({})".format(
-                ', '.join(['?']*len(txoids))
-            ), [is_reserved]+txoids
-        )
+        txoids = ((is_reserved, txo.id) for txo in txos)
+        await self.db.executemany("UPDATE txo SET is_reserved = ? WHERE txoid = ?", txoids)
 
     async def release_outputs(self, txos):
         await self.reserve_outputs(txos, is_reserved=False)
@@ -488,18 +489,12 @@ class BaseDatabase(SQLiteMixin):
             return addresses[0]
 
     async def add_keys(self, account, chain, keys):
-        sql = (
-            "insert into pubkey_address "
-            "(address, account, chain, position, pubkey) "
-            "values "
-        ) + ', '.join(['(?, ?, ?, ?, ?)'] * len(keys))
-        values = []
-        for position, pubkey in keys:
-            values.extend((
-                pubkey.address, account.public_key.address, chain, position,
-                sqlite3.Binary(pubkey.pubkey_bytes)
-            ))
-        await self.db.execute(sql, values)
+        sql = "insert into pubkey_address (address, account, chain, position, pubkey) values (?, ?, ?, ?, ?)"
+        values = (
+            (pubkey.address, account.public_key.address, chain, position, sqlite3.Binary(pubkey.pubkey_bytes))
+            for position, pubkey in keys
+        )
+        await self.db.executemany(sql, values)
 
     async def _set_address_history(self, address, history):
         await self.db.execute(