diff --git a/plugins/scaffolder-backend/src/scaffolder/tasks/NunjucksWorkflowRunner.test.ts b/plugins/scaffolder-backend/src/scaffolder/tasks/NunjucksWorkflowRunner.test.ts
index 61df2a167d..0ef0846ddb 100644
--- a/plugins/scaffolder-backend/src/scaffolder/tasks/NunjucksWorkflowRunner.test.ts
+++ b/plugins/scaffolder-backend/src/scaffolder/tasks/NunjucksWorkflowRunner.test.ts
@@ -25,6 +25,9 @@ import { ConfigReader } from '@backstage/config';
 import { TaskContext, TaskSecrets } from './types';
 import { TaskSpec } from '@backstage/plugin-scaffolder-common';
 
+// The Stream module is lazy loaded, so make sure it's in the module cache before mocking fs
+void winston.transports.Stream;
+
 const realFiles = Object.fromEntries(
   [
     resolvePackagePath(
diff --git a/plugins/scaffolder-backend/src/scaffolder/tasks/StorageTaskBroker.test.ts b/plugins/scaffolder-backend/src/scaffolder/tasks/StorageTaskBroker.test.ts
index 4cac2206fb..bb375e5a0f 100644
--- a/plugins/scaffolder-backend/src/scaffolder/tasks/StorageTaskBroker.test.ts
+++ b/plugins/scaffolder-backend/src/scaffolder/tasks/StorageTaskBroker.test.ts
@@ -187,7 +187,7 @@ describe('StorageTaskBroker', () => {
       .mockRejectedValue(new Error('nah m8'));
 
     const intervalId = setInterval(() => {
-      broker.vacuumTasks({ timeoutS: 2 }).catch(fail);
+      broker.vacuumTasks({ timeoutS: 2 });
     }, 500);
 
     for (;;) {