diff --git a/repos/mml/src/app/posix_playground/main.cc b/repos/mml/src/app/posix_playground/main.cc
index 3693857c21..4f175e8ef8 100644
--- a/repos/mml/src/app/posix_playground/main.cc
+++ b/repos/mml/src/app/posix_playground/main.cc
@@ -37,10 +37,10 @@ int main(void) {
     std::vector<Posix_playground::Chrono_thread*> thread_objs(4);
     std::vector<std::unique_ptr<std::thread>> thread_list(4);
 
-    for (int i = 0; i < 4; i++) {
-        Posix_playground::Chrono_thread thread_objs[i] = new Posix_playground::Chrono_thread(i);
+    for (std::uint16_t i = 0; i < 4; i++) {
+        thread_objs[i] = new Posix_playground::Chrono_thread(i);
         auto thread =  std::make_unique<std::thread>([&]
-                                      { thread_objs[i].execute(); });
+                                      { thread_objs[i]->execute(); });
         thread_list.push_back(thread);
         thread->join();
     }