diff --git a/include/condition_variable b/include/condition_variable
index 7d0b069..b1a50ee 100644
--- a/include/condition_variable
+++ b/include/condition_variable
@@ -163,7 +163,7 @@
 void
 condition_variable_any::notify_one() _NOEXCEPT
 {
-    {lock_guard<mutex> _(*__mut_);}
+    {lock_guard<mutex> __lx(*__mut_);}
     __cv_.notify_one();
 }
 
@@ -171,7 +171,7 @@
 void
 condition_variable_any::notify_all() _NOEXCEPT
 {
-    {lock_guard<mutex> _(*__mut_);}
+    {lock_guard<mutex> __lx(*__mut_);}
     __cv_.notify_all();
 }
 
@@ -188,8 +188,8 @@
     shared_ptr<mutex> __mut = __mut_;
     unique_lock<mutex> __lk(*__mut);
     __lock.unlock();
-    unique_ptr<_Lock, __lock_external> __(&__lock);
-    lock_guard<unique_lock<mutex> > _(__lk, adopt_lock);
+    unique_ptr<_Lock, __lock_external> __lxx(&__lock);
+    lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock);
     __cv_.wait(__lk);
 }  // __mut_.unlock(), __lock.lock()
 
@@ -210,8 +210,8 @@
     shared_ptr<mutex> __mut = __mut_;
     unique_lock<mutex> __lk(*__mut);
     __lock.unlock();
-    unique_ptr<_Lock, __lock_external> __(&__lock);
-    lock_guard<unique_lock<mutex> > _(__lk, adopt_lock);
+    unique_ptr<_Lock, __lock_external> __lxx(&__lock);
+    lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock);
     return __cv_.wait_until(__lk, __t);
 }  // __mut_.unlock(), __lock.lock()