diff --git a/packages/backend-core/src/queue/inMemoryQueue.ts b/packages/backend-core/src/queue/inMemoryQueue.ts
index 333accc985..62b971f9f5 100644
--- a/packages/backend-core/src/queue/inMemoryQueue.ts
+++ b/packages/backend-core/src/queue/inMemoryQueue.ts
@@ -63,12 +63,12 @@ class InMemoryQueue implements Partial<Queue> {
    * Same callback API as Bull, each callback passed to this will consume messages as they are
    * available. Please note this is a queue service, not a notification service, so each
    * consumer will receive different messages.
-   * @param func The callback function which will return a "Job", the same
    * as the Bull API, within this job the property "data" contains the JSON message. Please
    * note this is incredibly limited compared to Bull as in reality the Job would contain
    * a lot more information about the queue and current status of Bull cluster.
    */
-  async process(func: any) {
+  async process(concurrencyOrFunc: number | any, func?: any) {
+    func = typeof concurrencyOrFunc === "number" ? func : concurrencyOrFunc
     this._emitter.on("message", async () => {
       if (this._messages.length <= 0) {
         return