diff --git a/libcxx/utils/libcxx/test/features.py b/libcxx/utils/libcxx/test/features.py
--- a/libcxx/utils/libcxx/test/features.py
+++ b/libcxx/utils/libcxx/test/features.py
@@ -45,7 +45,13 @@
                                                                   #include <atomic>
                                                                   struct Large { int storage[100]; };
                                                                   std::atomic<Large> x;
-                                                                  int main(int, char**) { return x.load(), x.is_lock_free(); }
+                                                                  int main(int, char**) { (void)x.load(); return 0; }
+                                                                """)),
+  Feature(name='is-lockfree-runtime-function',  when=lambda cfg: sourceBuilds(cfg, """
+                                                                  #include <atomic>
+                                                                  struct Large { int storage[100]; };
+                                                                  std::atomic<Large> x;
+                                                                  int main(int, char**) { return x.is_lock_free(); }
                                                                 """)),
 
   Feature(name='apple-clang',                                                                                                      when=_isAppleClang),