diff --git a/packages/backend-core/src/queue/inMemoryQueue.ts b/packages/backend-core/src/queue/inMemoryQueue.ts
index 6c8107c7a4..985501bcbe 100644
--- a/packages/backend-core/src/queue/inMemoryQueue.ts
+++ b/packages/backend-core/src/queue/inMemoryQueue.ts
@@ -173,7 +173,7 @@ class InMemoryQueue implements Partial<Queue> {
   async waitForCompletion() {
     do {
       await timeout(50)
-    } while (this.hasRunningJobs)
+    } while (this.hasRunningJobs())
   }
 
   hasRunningJobs() {