diff --git a/src/PaymentServer/Persistence.hs b/src/PaymentServer/Persistence.hs
index 04ac8997b28c3e5b83fad91fde1df2167a358141..6f9548f9de135edeadd76171f9f71ab82271e94c 100644
--- a/src/PaymentServer/Persistence.hs
+++ b/src/PaymentServer/Persistence.hs
@@ -337,8 +337,9 @@ sqlite path =
       dbConn <- Sqlite.open (unpack path)
       let exec = Sqlite.execute_ dbConn
       exec "PRAGMA foreign_keys = ON"
-      exec "CREATE TABLE IF NOT EXISTS vouchers (id INTEGER PRIMARY KEY, name TEXT UNIQUE)"
-      exec "CREATE TABLE IF NOT EXISTS redeemed (id INTEGER PRIMARY KEY, voucher_id INTEGER, counter INTEGER, fingerprint TEXT, FOREIGN KEY (voucher_id) REFERENCES vouchers(id))"
-      return dbConn
+      Sqlite.withExclusiveTransaction dbConn $ do
+        exec "CREATE TABLE IF NOT EXISTS vouchers (id INTEGER PRIMARY KEY, name TEXT UNIQUE)"
+        exec "CREATE TABLE IF NOT EXISTS redeemed (id INTEGER PRIMARY KEY, voucher_id INTEGER, counter INTEGER, fingerprint TEXT, FOREIGN KEY (voucher_id) REFERENCES vouchers(id))"
+        return dbConn
   in
     return . SQLiteDB $ connect