Index: test/std/thread/thread.threads/thread.thread.class/thread.thread.constr/F.pass.cpp
===================================================================
--- test/std/thread/thread.threads/thread.thread.class/thread.thread.constr/F.pass.cpp
+++ test/std/thread/thread.threads/thread.thread.class/thread.thread.constr/F.pass.cpp
@@ -157,8 +157,11 @@
     {
         assert(G::n_alive == 0);
         assert(!G::op_run);
-        std::thread t((G()));
-        t.join();
+        {
+            G g;
+            std::thread t(g);
+            t.join();
+        }
         assert(G::n_alive == 0);
         assert(G::op_run);
     }
@@ -185,8 +188,11 @@
     {
         assert(G::n_alive == 0);
         assert(!G::op_run);
-        std::thread t(G(), 5, 5.5);
-        t.join();
+        {
+            G g;
+            std::thread t(g, 5, 5.5);
+            t.join();
+        }
         assert(G::n_alive == 0);
         assert(G::op_run);
     }
Index: test/std/thread/thread.threads/thread.thread.class/thread.thread.member/detach.pass.cpp
===================================================================
--- test/std/thread/thread.threads/thread.thread.class/thread.thread.member/detach.pass.cpp
+++ test/std/thread/thread.threads/thread.thread.class/thread.thread.member/detach.pass.cpp
@@ -29,8 +29,8 @@
     int alive_;
     bool done_;
 public:
-    static int n_alive;
-    static bool op_run;
+    static std::atomic_int n_alive;
+    static std::atomic_bool op_run;
 
     G() : alive_(1), done_(false)
     {
@@ -57,8 +57,8 @@
     }
 };
 
-int G::n_alive = 0;
-bool G::op_run = false;
+std::atomic_int G::n_alive = 0;
+std::atomic_bool G::op_run = false;
 
 void foo() {}