diff --git a/packages/aws-cdk/lib/list-stacks.ts b/packages/aws-cdk/lib/list-stacks.ts
index 533204adaf608..e76a1f393a0a9 100644
--- a/packages/aws-cdk/lib/list-stacks.ts
+++ b/packages/aws-cdk/lib/list-stacks.ts
@@ -81,7 +81,7 @@ export async function listStacks(toolkit: CdkToolkit, options: ListStacksOptions
             });
           }
         } else {
-          data.dependencies?.push({
+          data.dependencies.push({
             id: depStack.stackArtifacts[0].id,
             dependencies: [],
           });