diff --git a/repos/mml/src/app/thread_test/thread_test.cc b/repos/mml/src/app/thread_test/thread_test.cc
index 89a291349e..eccd44e671 100644
--- a/repos/mml/src/app/thread_test/thread_test.cc
+++ b/repos/mml/src/app/thread_test/thread_test.cc
@@ -72,7 +72,7 @@ public:
             _threads.insert(&thread->_list_element);
         }
         /* Test, whether unique_ptrs work */
-        auto unique_thread = std::make_unique<Test_thread>(env, 255, env.cpu().affinity_space().location_of_index(0));
+        auto unique_thread = std::unique_ptr<Test_thread>(new (_heap) Test_thread(env, 255, env.cpu().affinity_space().location_of_index(0)));
         unique_thread->start();
     }
 };