diff --git a/packages/@aws-cdk/aws-ecs/test/test.container-definition.ts b/packages/@aws-cdk/aws-ecs/test/test.container-definition.ts
index f5da5559c5d1b..1219baecada38 100644
--- a/packages/@aws-cdk/aws-ecs/test/test.container-definition.ts
+++ b/packages/@aws-cdk/aws-ecs/test/test.container-definition.ts
@@ -693,7 +693,8 @@ export = {
 
   'can add secret environment variables to the container definition'(test: Test) {
     // GIVEN
-    const stack = new cdk.Stack();
+    const app = new cdk.App();
+    const stack = new cdk.Stack(app, 'stack');
     const taskDefinition = new ecs.Ec2TaskDefinition(stack, 'TaskDef');
 
     const secret = new secretsmanager.Secret(stack, 'Secret');
diff --git a/packages/@aws-cdk/aws-ecs/test/test.firelens-log-driver.ts b/packages/@aws-cdk/aws-ecs/test/test.firelens-log-driver.ts
index 3aedf6de29831..fae333db80325 100644
--- a/packages/@aws-cdk/aws-ecs/test/test.firelens-log-driver.ts
+++ b/packages/@aws-cdk/aws-ecs/test/test.firelens-log-driver.ts
@@ -9,7 +9,8 @@ const image = ecs.ContainerImage.fromRegistry('test-image');
 
 export = {
   'setUp'(cb: () => void) {
-    stack = new cdk.Stack();
+    const app = new cdk.App();
+    stack = new cdk.Stack(app, 'stack');
     td = new ecs.Ec2TaskDefinition(stack, 'TaskDefinition');
 
     cb();