diff --git a/tests/legacy-cli/e2e/utils/project.ts b/tests/legacy-cli/e2e/utils/project.ts
index 7e7b1c9684a6..488e4ddd0f48 100644
--- a/tests/legacy-cli/e2e/utils/project.ts
+++ b/tests/legacy-cli/e2e/utils/project.ts
@@ -174,6 +174,7 @@ export function useCIDefaults(projectName = 'test-project') {
 
     if (appTargets.serve) {
       // Use a random port in serve.
+      appTargets.serve.options ?? = {};
       appTargets.serve.options.port = 0;
     }
   });