diff --git a/backend/src/util/TRANSACTIONS_LOCK.ts b/backend/src/util/TRANSACTIONS_LOCK.ts
new file mode 100644
index 000000000..847386e4d
--- /dev/null
+++ b/backend/src/util/TRANSACTIONS_LOCK.ts
@@ -0,0 +1,4 @@
+import { Semaphore } from 'await-semaphore'
+
+const CONCURRENT_TRANSACTIONS = 1
+export const TRANSACTIONS_LOCK = new Semaphore(CONCURRENT_TRANSACTIONS)