diff --git a/tests/sched_test.cpp b/tests/sched_test.cpp
index e70528e..9184026 100644
--- a/tests/sched_test.cpp
+++ b/tests/sched_test.cpp
@@ -56,7 +56,7 @@
   uintptr_t fake_child_stack[16];
   errno = 0;
   // If CLONE_THREAD is set, CLONE_SIGHAND must be set too.
-  ASSERT_EQ(-1, clone(child_fn, &fake_child_stack[16], CLONE_THREAD, NULL));
+  ASSERT_EQ(-1, clone(child_fn, &fake_child_stack[16], CLONE_THREAD, nullptr));
   ASSERT_EQ(EINVAL, errno);
 }