1 files changed, 6 insertions, 4 deletions
diff --git a/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/copy_ctor.fail.cpp b/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/copy_ctor.fail.cpp
index 4888fe90d92c..067302127cad 100644
--- a/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/copy_ctor.fail.cpp
+++ b/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.cons/copy_ctor.fail.cpp
@@ -16,14 +16,16 @@
 #include <mutex>
 #include <cassert>
 
-std::mutex m;
-
 int main()
 {
-    std::unique_lock<std::mutex> lk0(m);
-    std::unique_lock<std::mutex> lk = lk0;
+    {
+    typedef std::mutex M;
+    M m;
+    std::unique_lock<M> lk0(m);
+    std::unique_lock<M> lk = lk0;
     assert(lk.mutex() == &m);
     assert(lk.owns_lock() == true);
     assert(lk0.mutex() == nullptr);
     assert(lk0.owns_lock() == false);
+    }
 }